Peter Weingart

Christian Salzmann

Stefan Wörmann

The social embedding of biomedicine: an analysis of German media debates 1995-2004

Keywords: biomedicine, science and technology studies, media analysis, cloning, stem cell research, human genome project, social embedding

Biomedical research and technologies such as cloning, stem cell research, and the deciphering of the human genome have met with opposition-albeit of different intensity-motivated by ethical values. The debates over the continuation of research and the implementation of the respective technologies are being staged in the mass media. The media have assumed the function of "embedding" controversial knowledge and technologies into society by using public discourse. The hypothesis is that these discourses follow a common pattern revealing the process of "embedding," and ultimately leading to a change of existing values. In this study, three debates over cloning, stem cell research and the Human Genome Project are analyzed in ten German daily and weekly newspapers over the period 1995-2004. It is shown that the patterns of reporting are more complex than anticipated. Rather than being identical for all technologies, they reveal different courses depending on the kind of knowledge/ technology and value sensitivity.

The "embedding" of new knowledge and technologies through media debates

The public debates over new advances in biomedicine and options of their implementation reflect the complex process of "embedding" new knowledge and technologies in society. In particular cases where these options involve deep-seated values and ethical convictions-such as the dignity of the human embryo-these public debates are crucial for the success of the process of "embedding." By "embedding" we mean the process of the introduction of new knowledge and technologies and their subsequent adaptation to opposing values. The adaptation is mutual as both, technologies and values, change in the process. At the beginning of the process claims of scientists meet with both fears and enthusiasm on the part of the public expressed in the media. The crucial phase of the process, we believe, is the debate that is carried out to bring the often utopian visions and optimistic propaganda of the scientists in line with the fears and objections of the public as it is represented in and actively staged by the media. Only when that debate is more or less closed can one speak of a "normalization." The objective of our analysis, the results of which are to be reported below, was to identify the discursive mechanisms and argumentative resources which are employed when new knowledge and technology clash with societal values. We started with the hypothesis that in such cases debates follow a certain pattern: a first phase is characterized by far-reaching promises, even utopian visions of the implications of new research lines. These are met with value-bound resistance. The more utopian the promises, the more dystopian are the arguments in opposition to the new knowledge or technology. In a second phase of the debate, this value-bound resistance is gradually overcome as concrete research results are linked to individuals' interests. As we look here at three debates over biomedical knowledge, these interests pertain above all to health. Thus, strongly held general values such as the inviolateness of human nature are only upheld "as the moral barriers that they represent are technical barriers at the same time. Under the impact of new technologies the existing moral becomes outdated" (Van den Daele, 1985: 205). This process is complicated by the fact that we are dealing with different "morals" but also with different technologies [START_REF] Van Den Daele | Die Natürlichkeit des Menschen als Kriterium und Schranke technischer Eingriffe[END_REF]. Thus, the outcome may differ in the extent both to which values have changed and to which technologies have been adapted. The objective is to look at the patterns of interaction between scientifictechnical innovation and existing values proper.

In mass democracies, this process takes place in public debates staged by and in the media. Here, the media have the function of a forum, reflecting broad public opinion as well as organizing it. They are the public arena in which social, ethical and legal aspects of the implementation of new technologies are debated [START_REF] Neidhardt | The Public as a Communication System[END_REF]. Being independent entities the media operate according to their own criteria of relevance [START_REF] Staab | Nachrichtenwerttheorie: Formale Struktur und empirischer Gehalt[END_REF][START_REF] Eilders | Nachrichtenfaktoren und Rezeption: Eine empirische Analyse zur Auswahl und Verarbeitung politischer Information[END_REF]. At the same time, they play a key role in legitimating political decisions, in particular by staging debates, i.e. the presentation of different positions and the provision of arguments [START_REF] Gerhards | Zwischen Palaver und Diskurs: Strukturen öffentlicher Meinungsbildung am Beispiel der deutschen Diskussion zur Abtreibung[END_REF]. The legitimating function of the media is not restricted to politics but extends to science and technology as well. Value related resistance to certain research lines can undermine their legal and financial base and prevent further development [START_REF] Gregory | Science in Public: Communication, Culture, and Credibility[END_REF].

Given the centrality of the mass media in modern pluralist societies for staging public debates on controversial topics, such debates become an object of interest as an important mechanism of "embedding" new knowledge 1 into society. A whole series of studies has focused on the Human Genome Project (HGP), on "Dolly" and cloning as well as on other biomedical techniques. Even though they address different questions and proceed with different methodologies, many of their findings are relevant to our own. This is true even though these studies have been carried out in countries other than Germany. Some show very similar patterns, others reveal differences that can be explained with different values, legal conditions (cf. in the case of stem cell research) and political conditions. [START_REF] Nerlich | The Book of Life: How the Completion of the Human Genome Project was Revealed to the Public[END_REF] in their analysis of how the completion of the HGP was communicated to the public demonstrate the importance of value contexts and how scientists and policymakers play to them by using appropriate metaphors. However, similar patterns emerge with respect to the overall arguments either opposing or favoring the new technique: the "spectre of designer babies," although not explicitly mentioned in their material of British newspapers, "loomed large in the mid-market tabloid coverage," confronted by a "generally positive medical message" of curing major diseases and increasing life expectancy (Nerlich et al., 2002: 462). Analysis of reactions in the US (consumer telephone survey and media analysis) shows a very similar ambivalence to the new knowledge and sees it reflecting the same division into a "Discourse of Great Promise" and a "Discourse of Concern" that Durant, Hansen and Bauer had already observed in early focus groups (Tambor et al., 2002: 35;[START_REF] Durant | Public Understanding of the New Genetics[END_REF]. Human cloning, even though not mentioned in the press in connection with the HGP, was nonetheless on the minds of respondents. According to the authors, this supports a remark by Francis Collins, head of the HGP, that people tend to "lump anything with 'gen' as the human genome project-gene therapy, GM foods, cloning-it's all the same thing" (cited in Tambor et al., 2002: 36).

The debate on cloning is still more sensitive, the fears associated with cloning reach deep, and they are connected to "mistrust in scientific endeavor, in the motives of scientists, and in existing systems of regulation and legislation" (Petersen, 2002: 73). Scientists emphasize the medical benefits of cloning, too, and the media frequently report about their optimistic views but especially in the case of cloning the climate of positive opinion is hard to sustain. After the announcement of Dolly, reporting in Australian papers, for instance, highlighted the dangers of human cloning and the need to regulate cloning research. "Stories 'framed' the issue largely in terms of risk and imminent threat" (Petersen, 2002: 85). The activities of pseudo-scientists such as Richard Seed and Brigitte Boiselier of the Raelian sect that claimed to have achieved or were just about to clone human babies and similar announcements of the credentialed American fertility experts Zavos and Antinori contributed to a cloning hype throughout 2001 that raised already existing anxieties to even higher levels [START_REF] Nerlich | Anatomy of a Media Event: How Arguments Clashed in the 2001 Human Cloning Debate[END_REF]. All of these media events reveal both commonalities and differences. They are, furthermore, all examples of what we refer to as processes of "embedding" of new knowledge. The objective is to identify the patterns and mechanisms that create them.

Research into discourses on such diverse issues as nuclear energy [START_REF] Gamson | Media Discourse and Public Opinion on Nuclear Power: A Constructionist Approach[END_REF], abortion [START_REF] Gerhards | Zwischen Palaver und Diskurs: Strukturen öffentlicher Meinungsbildung am Beispiel der deutschen Diskussion zur Abtreibung[END_REF], the legalization of drugs [START_REF] Weßler | Öffentlichkeit als Prozeß: Deutungsstrukturen und Deutungswandel in der deutschen Drogenberichterstattung[END_REF], and climate change [START_REF] Weingart | Von der Hypothese zur Katastrophe: Der anthropogene Klimawandel im Diskurs zwischen Wissenschaft, Politik und Massenmedien[END_REF] allows a number of conclusions about the dynamics of such discourses.

• The issue in such discourses is not finding the better argument. Rather the discourse evolves under the operative conditions of the mass media. • Arguments and their value references appear only in "bits and pieces" (Weßler, 1999: 70). Owing to permanent references to previous arguments, fragmentary statements can only be analyzed in the context of larger text corpora [START_REF] Entman | Framing: Toward Clarification of a Fractured Paradigm[END_REF]. • In the case of subjects that present dilemmas, the discourse tends to become moralizing which makes the legitimation of (political) decisions more difficult. • In any discourse, "fragmented bits of understanding reality" (Hajer, 1993: 41) come together and different arguments and positions may coalesce to a cluster which subsequently becomes the reference for all further arguments. These clusters assume the function of a storyline for a group of actors, together with adjoining problem definitions, attributions of causes and problem solutions. If there is discursive closure such a storyline can dominate so much that it is binding for the participants in the discourse [START_REF] Weingart | Von der Hypothese zur Katastrophe: Der anthropogene Klimawandel im Diskurs zwischen Wissenschaft, Politik und Massenmedien[END_REF]. • Owing to the limited attention of the media and their audiences, symbols, metaphors and keywords, i.e. abbreviated representations of more complex interpretive patterns, have an important function. • Only few communicated events provoke sufficient reactions from actors that, in turn, trigger counter reactions so that, for example, a "climate change discourse" evolves that remains stable over some time and serves as a news value for the media.

During the first half of the 1990s the leading German media paid increased attention to the topic of biomedicine [START_REF] Kohring | Das Bild der Gentechnik in den internationalen Medien: Eine Inhaltsanalyse meinungsführender Zeitschriften[END_REF][START_REF] Hampel | Germany[END_REF]. 2 With the deciphering of the human genome the volume of reporting in the media has increased even further. Not only are the medical and scientific implications (i.e. potential forms of therapy) being discussed but so also are the social, ethical and legal aspects linked to them. Thus, in the case of stem cell research the issue of human dignity is discussed together with the issue of the freedom of research or the right to health. 3 The debate on embryonic stem cell research is carried out in the newspapers, above all the Frankfurter Allgemeine Zeitung (FAZ) with such intensity that the former president of the Max Planck Society was suspicious of a synchronized bioethical campaign of German daily newspapers [START_REF] Markl | Freiheit, Verantwortung, Menschenwürde: Warum Lebenswissenschaften mehr sind als Biologie[END_REF].

Although this study focuses on the media debates only and leaves the political context aside, one remark is warranted. The intensity with which the debate on stem cell research was carried out in Germany is often explained with that country's particular sensitivity about its past. Indeed, recent developments of biomedical techniques clearly raise the specter of eugenics. A 1991 exhibition, not in Germany but in Paris, made the point already: "Today, astounding paradox, the generation following Nazism is giving the world the tools of eugenics beyond the wildest Hitlerian dreams" (M. Vaquin, cited in Kevles, 2000: 180). Albeit, at least to our knowledge not established by systematic empirical data but based on impressionistic perception of media coverage, it is highly probable that references to Nazi crimes in connection with eugenics are more frequent here than in the Anglo-Saxon countries and contribute to a heightened level of alarm in the German public with respect to potential abuses of biomedical techniques such as the use of embryos in stem cell research or cloning.

The multilayered quality of the debate is due to the fact that biomedicine cuts across a whole series of applications (Dolata, 1998: 144). This is exemplified in the area of molecular medicine. Embryos that are produced in artificial insemination and are not transferred into the uterus may be used as a basis for the production of human embryonic stem cells. The technique of artificial insemination is also a condition for preimplantation diagnosis (PID) which was clinically implemented successfully for the first time in 1990 [START_REF] Handyside | Pregnancies from Biopsied Human Preimplantation Embryos Sexed by Y-specific DNA Amplification[END_REF]. The discussion about PID and other genetic tests is tightly linked to progress in the Human Genome Project which, in turn, is the basis for the discovery of genes causing diseases. In the discussion about stem cell research one finds references to the possibilities of therapeutic cloning, and since 1997 reproductive cloning-in the cloned sheep "Dolly"-is an important referent in the public debate on genetic engineering because it signals the possibility of the cloning of humans [START_REF] Mieth | Probleme der Ethik in der Biomedizin am Beispiel der Klonierungsdebatte[END_REF][START_REF] Kollek | Klonen ist Klonen-oder nicht? Warum der erste Menschenklon nicht die Gestalt ist, an der sich die Urteilsfindung orientieren muß[END_REF].

The debate on the different strands of biomedical research and technology has been until very recently the dominating public debate related to science and may therefore be taken as a paramount example of the "embedding" of new knowledge into society.

Scope and methodology of the study

The empirical base of the study is the reporting on biomedicine in ten daily and weekly German newspapers over the period between 1995 and 2004. 4 A quantitative analysis is based on a set of 26 keywords and clusters of keywords that could be searched electronically. With these data we have comprehensive information about media attention to biomedicine over the entire period and not just about the debates surrounding it.

A second part of the quantitative analysis differentiates the material on biomedicine and focuses on three debates: the cloned sheep "Dolly" (1997: 199 articles), 5 the Human Genome Project (2000: 360 articles), and stem cell research 6 (2001-2: 931 articles). Debates are communications that last for a certain time, are carried out in several media, and comprise a certain number of articles dealing with the same issue. Again, the curves gained from the number of articles on the respective issue that appeared day by day indicate the level of attention. They can be linked to specific events that explain particular peaks. The overall shape of the curves reveals the course of "issue attention" over the duration of the entire debate. They were coded according to source, author, origin of author, date, title, section, topic and subtopic, and occasion. 7 The qualitative content analysis [START_REF] Mayring | Qualitative Inhaltsanalyse[END_REF] focuses on a more detailed look at the debates. The reconstruction of the debates requires a differential weighting of articles. While mere reports are included, opinion pieces such as commentaries and lead articles are deemed more important. The chronological analysis of these articles serves to trace the course of the debate as well as the arguments and positions of diverse actors. The analysis is strictly chronological, done by two coders separately. Typical quotes were identified by both, then interpreted and followed by a subsequent analysis. The qualitative analysis was oriented by the following guiding questions:

• Which event triggers the reporting?

• Which actors are speaking?

• What share of the article is being taken by comments and what is their tenor?

• What are the central issues of conflict in the debate?

• What are the respective arguments on the "pro-" and "contra-" sides?

• Where is the boundary between the technically possible and the politically and ethically acceptable being drawn?

The methodology thus combines quantitative and qualitative content analysis. The thesis is that debates share a common pattern: the beginning of a debate is characterized by a general, ethically based resistance to the new knowledge/technology in question. Subsequently the conflict between ethical values and the new knowledge/technology is gradually resolved by referring it to detailed problems such as concrete forms of implementation. The ethical resistance is gradually overcome by appeals to piecemeal applications. The technology is not being rejected but, instead, the values are adapted to it.

Results

Quantitative analysis

A first overview shows that media attention for biomedicine has grown dramatically around the year 2000. Based on the occurrence of four keywords-biomedicine, stem cells, cloning, and Human Genome Project (with respective truncations) 8 -the curves show the increase of attention around 2000 (and the subsequent decrease) (Figure 1). The differences are also instructive. Stem cells and cloning attract most attention.

Cloning is a special case, however. It attracted media attention since the announcement of Dolly's birth in 1997. 9 But since then the metaphorical use of the term "cloning" has increased, i.e. it has been used in many other contexts which explains why it appears in many non-technical articles.

It is also notable that the intensity of media reporting is and remains higher in the case of stem cells and cloning than for the Human Genome Project. Generally, the news value of biomedicine has increased so that relatively small events have a higher probability of being reported.

In order to find debates, we looked at the frequency curve for five keywords-stem cell, cloning, bioethics, National Ethics Council (Nationaler Ethikrat, NER), and PID-in twoweek intervals. Thus, peaks could be identified in clearly demarcated time spans. 10 These are taken to be debates. However, the frequency curves are only representations of the media career of a concept. The ultimate identification of a debate can only be achieved by analyzing concrete articles. Three debates were thus identified: cloned sheep "Dolly" (24 February-12 June 1997), 11 the cracking of the human genome (3 April-31 December 2000), 12 and stem cell research (1998-2002 with the emphasis on the period 2001-2). 13 Obviously, the operational definition of a debate does not cover the actual extension of the debates on each of the three topics but is limited to the time period for which the intensified media reporting could be observed. Debates over cloning reach back at least to the late 1970s when the perspective of cloning moved closer by the advances of molecular biology triggering fictitious reports of the successful cloning of humans [START_REF] Rorvik | his Image: The Cloning of a Man[END_REF]. The same is true for the Human Genome Project albeit not in that particular form. But visions of the identification of specific genes and their functions date back to Mendel's discovery of heredity although the obstacles seemed insurmountable. Resistance to applications of respective techniques has been provided by many authors even before their concrete availability (e.g. [START_REF] Etzioni | Genetic Fix: The Next Technological Revolution[END_REF]. These precursors to the much more recent debates reflected in our media coverage will go unmentioned in this analysis even though some aspects of the pattern we are looking for-such as the initial utopian promises and dystopian opposition-may actually have taken place then. This must be kept in mind when interpreting the patterns of the attention cycles presented below.

The quantitative data about the three debates show quite different patterns. The "cloning debate" follows the somewhat expected course (Figure 2). The initial peak reflecting the presentation to the press of "Dolly," the cloned sheep, is followed by a series of ever smaller peaks related to different political events, the first of which is a unanimous vote by the German parliament, the Bundestag, banning the cloning of humans. With this the debate is practically over as the consensus against cloning is nearly complete. A closer look shows that a few voices wanted to keep open the option of therapeutic cloning which may signal a future revival of the debate and the embedding of cloning on the health ticket.

The "human genome project" debate reveals a quite different pattern (Figure 3). One peak at the beginning in April 2000 was triggered by Craig Venter's press announcement that he had already cracked the code. This attracted media attention not because the technology raised moral opposition but because the competition between publicly funded and private research was at issue. The second and only other significant peak in June 2000 was caused by the press conference of Bill Clinton and Tony Blair where the two statesmen declared all data from the project to be made publicly accessible. If there was an ethical issue, it pertained to the opposition against the commercialization of the human genome data, i.e. a regulatory issue. The debate over "stem cell research" shows yet another pattern (Figure 4). Triggered by the declaration of the German science funding agency (DFG) that it wanted to import stem cells, the subsequent debate is characterized by a series of peaks that indicates a relatively high level of media attention over the entire length of the debate. It ends with the decision of the German Bundestag at the end of January 2002 to ban the production of new cell lines and to allow research with imported cell lines only. This shows that the entire debate was closely linked to that particular decision and depended on its outcome.

Qualitative analysis

The debates were then analyzed according to the guiding questions (cf. above) in order to identify common patterns and differences.

Cloning On 23 February 1997, the British scientist Ian Wilmut announced the first mammal cloned from a differentiated cell. With this innovation the conviction that no new life could be created from differentiated cells was refuted. Wilmut's presentation of Dolly initiated the media debate in 1997. Already the first report in the tabloid Bild made reference to the cloning of humans which subsequently became the horror scenario around which the entire debate developed. The cloning debate is special in the sense that the utopian vision of cloning is actually a dystopia in the eyes of virtually every participant in the debate. Science has moved closer to the dream of the reproduction of life.

A NIGHTMARE! (Bild, 24 February 1997)

The birth of the sheep Dolly is a beacon like the first nuclear explosion. The cloned human must not be. (Handelsblatt, 27 February 1997, p. 2) "Now everything is doable". With the appearance of the cloned sheep "Dolly" a dam seems broken: Identical copies also of humans will be producible in whatever numbers. (Der Spiegel, 10/1997(3 March 1997), p. 216)

Wilmut himself admitted that the possibility of cloning humans had become real and called for "unequivocal laws" to prevent this (Der Spiegel, 10/1997(3 March 1997), p. 220). In fact, his achievement opened the door to high-tech eugenics. Thus, one option would have been that cloning would be launched with a utopian eugenic perspective. Instead, the rejection of cloning humans was unanimous. The common reason was that cloning conflicts with human dignity and individuality. Fewer are the visions that cloning would have negative consequences for society if only the good, beautiful and rich would be cloned. These social dystopias are nearly always linked to the breaking of a taboo. If this happened, thus the argument, such a development would end with Huxley's Brave New World.

The chimera of a terrible creature is loose, as disgusting as Frankenstein's monster and as threatening as Godzilla: human clones, we have learned, could be created within two years. This vision is dreadful for everyone. (FAZ, 11 April 1997, p. 35) There are very few proponents of the technology, and they do not propagate cloning humans.

Rather they argue against an absolute ban on cloning because it would close the door to therapeutic cloning with its many options for curing diseases. This reference to medical applications of cloning and the journalists' doubts about the possibility to stabilize an absolute ban over time already signal in which direction one can expect the embedding of therapeutic cloning to go.

The public reacts to "Dolly" with moral nightmares. All of a sudden the breeding fantasies return that belonged to the literature of the 19 th and early 20 th centuries: the double, the homunculus, machine man-it is as if concern with this freaking zoo had only been delayed … In Scotland is a sheep. It is supposed to produce proteins, maybe also milk, meat and wool. But the talk is about humans.

In medicine moral imagination comes into trouble. The fantasies lose part of their threatening nature when the curing or even only the containment of diseases is at issue. (FAZ, 27 February 1997, p. 39) All false alarm? No one thinks about cloning humans? We should not be appeased too easily. As so often there could be "appliers" who propagate the doable so long until we take it to be the desirable-and indispensable to secure the economic position! (SZ, 26 February 1997, p. 4) The rejection of cloning is accompanied by comments from journalists that the new technique will ultimately be realized against resistance, be it by mad scientists and/or totalitarian states. Der Spiegel commented that the ban on cloning humans will not be easily upheld in view of therapeutic reproductive applications in the case of female infertility, and that researchers had already prepared the ideological terrain for "man to measure" by postulating the power of the gene (Der Spiegel, 10/1997(3 March 1997)

, p. 222).

Der Spiegel: There is great fear that the technique will be abused. Wilmut: This fear is completely justified. We have said from the beginning: With our technique we can produce genetic copies of humans. Only unequivocal laws can prevent that. (Der Spiegel, 10/1997(3 March 1997), p. 220)

A worldwide proscription of the cloning of humans will hardly be reached. There are too many potential clients who are fascinated by the idea and who would pay substantial sums for a clone. (SZ, 30 April 1997, p. 4) "It will not be possible to stop cloning", declares US-biologist Lee Silver. "Now, everything is doable, all limitations have collapsed." (Der Spiegel, 10/1997(3 March 1997), p. 219)

The question of all questions reads: will legal barriers that are porous anyway hold permanently? Will society and its concept of the permissible … not change so much in the next one to two decades that, for example, the "law protecting embryos" of 1990 will not seem "up to date" anymore? (FAZ, 26 February 1997, p. 1) Human Genome Project The debate over the decoding of the human genome differs from the others because as a scientific achievement it was hailed more or less unanimously. The beginning of the debate was not the press conference at which the final success was announced. Instead it began already in early 2000 with hints from Craig Venter that his company had decoded 99 percent of the human genome. Subsequently, four issues were discussed: 1) To what extent is Venter's assertion credible, and what is the quality of his data? 2) To what extent may parts of the human genome be patented? 3) What are the implications of the competition between public and privately funded science? 4) In connection to gene chips and genetic screening: how is one to deal with knowledge about one's genes vis-a-vis insurance companies and employers? At the press conference of 26 June 2000, Bill Clinton and Tony Blair announced the end of the race between public and private research for the genome and promised future collaboration. Subsequently, the question of how to deal with the new knowledge moved to the foreground. Many authors called for an ethical research that would make it possible to identify and to react to problems created by this new knowledge as early as possible.

Two aspects were the focus of the debate throughout. Critics of the new knowledge warned of a new eugenics that would spread in reaction to individual demand. In due course this would lead to pressure on individuals with a genetic defect who would have to justify themselves for their condition. At the same time, the danger is cited that knowledge about the genome will feed the readiness to intervene into the human gene pool. 14 This scenario is regarded as the breach of an ethical barrier and represents the dystopia.

Unfortunately we have prepared an entire generation of children for a new eugenic era by having indoctrinated them: You are your genes. (Jeremy Rifkin in an interview in SZ, 9 August 2000, p. 15) For the time being the barrier against cloning of humans and interventions into the germ line holds-but there are already noisy protests against the latter. (Jens Reich in Die Zeit, 27/2000 (29 June 2000), p. 1) Once God's image, now gene-construct … Only extreme control and discipline could prevent that people would be discriminated because of their genome. (Die Welt, 8 April 2000, p. 10) Those in favor argue that the new knowledge about the genome will lead to entirely new therapeutic possibilities, above all individualized medications. We see the day coming that therapies like radiation and chemotherapy with their treacherous side effects and uncertainties will be medical anachronisms. This day will not be tomorrow or next year. And it cannot be brought about by one person, firm or organization. The revolution needs more than one soldier. (Craig Venter in FAZ, 8 April 2000, p. 43) Again, the emphasis is on individual health interests being served by the new knowledge rather than collective measures that are the core of the dystopian images painted by the critics.

Stem cell research

The crucial phase of the debate over stem cell research lasted from 4 May 2001 to 2 February 2002, in spite of the fact that the technology to multiply and cultivate stem cells had been available since the fall of 1998. Before the crucial phase of the debate began, the media had discussed at a relatively low volume various problems related to stem cells. The positive and critical arguments that had been offered during that time did not change essentially in their structure in the crucial phase starting May 2001. This phase was initiated by a declaration of the German Science Foundation (DFG) calling upon legislators to "allow the import of pluripotent stem cell lines produced abroad" (DFG, 2001). The central issue of the debate that followed was if research on embryonic stem cells was to be permitted. Linked to that issue was the question whether they could be produced for research or if they could at least be imported.

The critics of stem cell research argued unanimously that the human embryo had a moral status and, thus, must not be "produced" only to be used and discarded later. Human life began with the fusion of egg and sperm cell, thus, research on embryos was not permissible.

"The freedom of research is not without limits". Herta Däubler-Gmelin says, no embryo may be sacrificed for vague future visions of cure. (interview with the minister of justice, SZ, 12 May 2001, p. 8) The proponents use a diverse array of arguments. One line appeals to economic reasons: to prevent stem cell research would jeopardize Germany's position in the globalized economy. Another strategy is to refer to existing regulations and practice with regard to abortion and other techniques of reproductive medicine. The main line of argumentation, however, is once again the appeal to health interests. A possible revolution in medicine is promised however cautiously. Once stem cell research achieved maturity, individualized therapy of organs would be feasible.

Because stem cells are flexible, brain, kidney and heart cells could be grown from them and used for the repair of damaged organs. Maybe no patient would have to die while being on a waiting list for donor organs. (FAZ, 24 January 2001, p. 11)

Discussion

The comparison between the three debates shows a number of both commonalities and differences. Biomedical research is news for the media. Media attention to biomedicine has intensified, and so have the debates over particular aspects of biomedical techniques. 15 (This must be seen in perspective, however. The share of science related articles is relatively small, c. 5 percent, and that of medicine related ones is even smaller [START_REF] Kohring | Wissenschaftsjournalismus: Forschungsüberblick und Theorieentwurf[END_REF].) Most of the attention is paid to cloning and to stem cell research, a finding that is supported by the parallel analysis of biomedicine in television news [START_REF] Ruhrmann | From the Scientific to the Political Benefit Controversy? Molecular Medicine in German TV-News 1995-2004[END_REF]. The reason lies most likely in the controversial nature of these two technologies.

The debates all focus on conflicts between new knowledge and institutionalized ethical values, but nevertheless the foci differ. Not in all cases was the announcement of new knowledge or a new technology the actual reason for the beginning of the debate. The stem cell debate in the media was triggered by the DFG announcement about the import of stem cells. Although the promises of medical applications appear to be fairly concrete, the ethical opposition was based on an even more concrete violation of the principle of human inviolability backed, in the German case, by existing legal provisions. This explains why the debate was more intense than the other two were.

In the case of the HGP, the actual issue of contention was the "patentability of life" that seemed to arouse opposition, and became an issue in the media because it was Craig Venter representing private business who claimed to have completed the deciphering of the code. A fear connected to this is the vision of the "gene chip" that would violate the solidarity principle and the right to self determination. The utopian scenario of a "eugenics from below" is ambivalent. Promises of an individualized medicine, fine-tuned to the genetic make-up of the patient, are countered by fears that illness will become biological fate and force the unfortunate ones to justify their condition. 16 The HGP clearly triggers fewer ethical concerns than the two other technologies so that the medical promises connected with it seem to be more convincing.

The "Dolly" debate is over the future implications of cloning. In this case the utopian vision of the cloning of humans is quickly turned into a dystopia. 17 Arguments in defense of the technique that point to the potential applications for the cure of inheritable diseases are rare. The horror of the duplication of humans and the loss of human dignity is (still) greater than the distant and uncertain promises of the cures through therapeutic, let alone germinal cloning. It may be speculated that the cloning debate is still in its early stages.

The number and origin of actors participating is quite different from debate to debate. It reflects not only the interests involved but also, to an extent, the publics that are involved as well as the scope of their involvement.

In the debate over stem cell research a greater number of scientists and policymakers was involved while only few representatives from the church and other social organizations could position themselves. The debate over "Dolly," on the other hand, is shaped primarily by policymakers, and only few scientists took part. The great number of scientists taking part in the stem cell debate may be responsible for the fact that media reporting in this debate is very evenhanded. One indicator of the state of the debate is statements in the media about the expected social reactions to the knowledge or technology in question. These speculations point to the mechanisms by which the opposition will eventually be overcome, and in what ways the values will change. The "slippery-slope" argument typically accompanies all controversial technologies and already signifies the possible breakdown of the values that stand in their way. It is the argument that characterizes an early phase in the embedding of new knowledge and technology when the utopian/dystopian dichotomy is still the line of conflict. When the debate has moved to more detailed and concrete issues, the "slippery-slope" rhetoric is no longer appropriate. Then, questions of regulation become dominant. This does not mean that consensus has already been reached. In fact, the more pressing the need for regulation is perceived, the more concrete the arguments are against the research or technology. It is in this phase that the process of value change actually takes place. This would also agree with the analysis of biomedicine in television news where the shift of actors from scientists to policymakers and ethicists as well as a shift from benefit to more risk-oriented reporting seem to indicate an increasing politicization and a growing concern about the risks of the new techniques [START_REF] Ruhrmann | From the Scientific to the Political Benefit Controversy? Molecular Medicine in German TV-News 1995-2004[END_REF].

Our initial hypothesis that the social embedding of new knowledge and technologies would follow the same pattern has proven to be too simple. Of the three debates analyzed here, only one ("Dolly") comes close to the pattern we expected. Even there we can only observe the wide gap between utopian visions and dystopian opposition early on whereas the prospect of cloning humans does not become accepted and "normalized." However, the door is left open to the cloning of embryos for medical purposes. Two reasons are likely to be responsible for the seemingly divergent patterns. One is the research design itself. The debates we observed as they appeared in the media analysis were probably at different stages of their development. In other words, it is necessary to extend the time period considerably if one wants to capture the entire process of "embedding" of new knowledge as we defined it above. None of the debates, cloning, stem cell research and even the HGP, can be considered "closed" at this time. As new applications are developed, discussions about their acceptability will surely flare up again. The second, obvious reason is the different nature of the technologies and their impact on dominant values. The HGP has raised much less opposition than stem cell research and cloning, and opposition to the latter is stronger and more unanimous than against stem cell research. In the case of Germany where the debate on and opposition to stem cell research was more intense than in the UK, this may be explained partly with the "spectre of eugenics" already mentioned above, and partly with the different legal context ("law to protect embryos").

However, there is one obvious commonality between all three debates: in all of them the trail to ultimate realization of the technologies in question is blazed with promises of medical advances, and these are perceived as the reasons that will ultimately legitimate the breach of ethical barriers. Thus, further research will have to look at each case in more detail in order to identify the particular relationship between the new knowledge in question and the values affected by it. However, we see the advantage and the novelty of our study in the fact that we have looked comparatively at three different debates over three different types of knowledge. Such a comprehensive approach appears warranted in order to overcome the well-known limitations of case studies. Notwithstanding their differences, the issue is to not lose sight of the similarity between the cases: namely, that with the introduction of new biomedical knowledge into society, general ethical values such as the integrity of human nature are overcome by more mundane ones such as health and relief of suffering. contexts (e.g. for Australia see [START_REF] Petersen | Replicating our Bodies, Losing our Selves: News Media Portrayals of Human Cloning in the Wake of Dolly[END_REF]. Cf. remarks above on studies of cloning.

Figure 1 .

 1 Figure 1. Media attention to biomedicine 1995-2004.

Figure 2 .

 2 Figure 2. Debate over cloning.

2 3Figure 3 .

 23 Figure 3. Debate over the HGP.

Figure 4 .

 4 Figure 4. Debate over stem cell research.

Public Understanding of Science 17 (3)

The studies of[START_REF] Kohring | Das Bild der Gentechnik in den internationalen Medien: Eine Inhaltsanalyse meinungsführender Zeitschriften[END_REF] and[START_REF] Hampel | Germany[END_REF] show this for all of biotechnology whereas we deal with biomedicine only.

A longitudinal media analysis dealing with gene transfer into human cells for 1970-2001 shows the importance of health interests[START_REF] Voss | Die Gentherapie im Spiegel der Presse von 1970 bis 2001[END_REF].

Frankfurter Allgemeine Zeitung (FAZ), Süddeutsche Zeitung (SZ), Bild, Westdeutsche Algemeine Zeitung (WAZ), Die Welt, die tageszeitung (taz), Handelsblatt, Der Spiegel, Focus and Die Zeit.

The corpus of Dolly contains all articles with reference to the cloned sheep Dolly. This is different from the articles that merely contain the keyword "cloning."

6 We concentrate on two papers-Frankfurter Allgemeine Zeitung (FAZ) and Süddeutsche Zeitung (SZ)-because of the large amount of articles dealing with stem cell research.

Analyzing articles of Die Zeit and Frankfurter Rundschau[START_REF] Doring | A Sequence of 'Factishes': the Media-Metaphorical Knowledge Dynamics Structuring the German Press Coverage of the Human Genome[END_REF] points out that the media coverage of the HGP is characterized by images of a new biological determinism.

A similar media trend for the American press could be identified by[START_REF] Nisbet | Biotechnology and the American Media: The Policy Process and the Elite Press, 1970 to 1999[END_REF] for the area of biotechnology (including "green" biotechnology).

A study of British media discourse shows similar patterns[START_REF] Smart | Reporting the Dawn of the Post-genomic Era: Who Wants to Live Forever?[END_REF].

Acknowledgements

This paper is based on research funded by the German Federal Ministry of Education and Research (BMBF) in the framework of the program "Research on the Ethical, Legal, and Social Aspects of Molecular Medicine."

Notes

We thank Miriam Voss and three reviewers for critical and constructive comments. 1 The term "new knowledge" implies new scientific knowledge, technical artefacts and techniques. In this context the term "debate" means "public communications of actors about themes, positions and arguments related to them as well as communications about other actors" (Gerhards and Lindgens, 1995: 1).

Weingart et al.: Social embedding of biomedicine 389 28-APR-2001 05-MAY-2001 10-MAY-2001 16-MAY-2001 22-MAY-2001 29-MAY-2001 03-JUN-2001 09-JUN-2001 16-JUN-2001 22-JUN-2001 28-JUN-2001 04-JUL-2001 10-JUL-2001 16-JUL-2001 21-JUL-2001 27-JUL-2001 02-AUG-2001 08-AUG-2001 14-AUG-2001 21-AUG-2001 28-AUG-2001 05-SEP-2001 12-SEP-2001 21-SEP-2001 29-SEP-2001 12-OCT-2001 23-OCT-2001 30-OCT-2001 06-NOV-2001 12-NOV-2001 19-NOV-2001 26-NOV-2001 01-DEC-2001 07-DEC-2001 13-DEC-2001 19-DEC-2001 31-DEC-2001 08-JAN-2002 14-JAN-2002 19-JAN-2002 25-JAN-2002 31-JAN-2002

Authors

Peter Weingart is professor of sociology, sociology of science, and science policy studies at Bielefeld University. He was director of the Center for Interdisciplinary Research (ZiF: 1989-94) and is director of the Institute of Science and Technology Studies (IWT: 1993-) at Bielefeld, and is a member of the Berlin-Brandenburg Academy of Science. Correspondence: Universität Bielefeld, Fakultät für Soziologie, P.O. Box 10 01 31, D-33501 Bielefeld, Germany; e-mail: weingart@uni-bielefeld Christian Salzmann is doctoral candidate at the Institute for Science and Technology Studies (IWT) at Bielefeld University. His main research interests are media analysis, popularization of science and science and technology studies. His doctoral thesis deals with popular scientific journals.

Stefan Wörmann is doctoral candidate at the Institute for Science and Technology Studies (IWT) at Bielefeld University. His main research interests are media analysis, science and technology studies and political communication. He is working on a doctoral thesis on the role of scientists in the media.


Holger Schütz

Peter M Wiedemann

Framing effects on risk perception of nanotechnology

Keywords: risk perception, nanotechnology, benefits, framing, social characteristics

How do people judge nanotechnology risks that are completely unfamiliar to them? Drawing on results of previous studies on framing and risk perception, two hypotheses about potential influences on nanotechnology risk perception were examined in an experimental study: 1) Risk perception of nanotechnology is influenced by its benefit perception. 2) Risk perception of nanotechnology is influenced by the context in which nanotechnology is embedded, specifically by the characteristics of the enterprises that profit from nanotechnology: large multinational enterprises versus small and medium-sized enterprises. In contrast to findings for other new technologies, e.g. biotechnology, the different types of benefit did not affect risk perceptions in our study. However, we found that characterizing the enterprises as large multinational versus small or mediumsized leads to differences in risk perception. One can speculate that when personal knowledge about a technology is lacking, people use more familiar aspects from the social context as cues for their risk evaluation.

Introduction

Nanotechnology is widely recognized as one of the key technologies of the twenty-first century [START_REF] Paschen | Nanotechnologie-Forschung, Entwicklung, Anwendung[END_REF]EU, 2004). Nanotechnology stretches across the entire spectrum of science and technology-with research and applications in physics, chemistry, engineering and electronics, as well as medicine. For example, nanotechnology provides the basis:

• for ever smaller data storage devices while at the same time increasing memory capacity;

• for highly efficient filters for wastewater treatment;

• for photovoltaic windows;

• for new materials allowing the automotive industry to produce ultra light engines and car body panels; and • for artificial joints whose nano surface coatings can be tolerated better by the human body (BMBF, 2004).

The discussion of risks, however, is closely tied to the discussion of opportunities. Prominent critics-among them Bill Joy and Michael Crichton-warn of the potential risks associated with nanotechnology. In the year 2000, Bill Joy received public attention for his horror vision published in the magazine Wired where he envisions self-replicating nanorobots that, after having transformed all living organisms into nanosubstances, will leave behind a broad trail of destruction in the form of "gray goo." Michael Crichton drew up a gloomy scenario in his science-fiction thriller Prey. Nanorobots, designed by the military, escape from the laboratory to unite in swarms and attack humans.

In Europe, the political debate about the risk potentials of nanotechnology started in 2003. It was initiated in particular by Greenpeace [START_REF] Arnall | Future Technologies, Today's Choices. Nanotechnology, Artificial Intelligence and Robotics: A Technical, Political and Institutional Map of Emerging Technologies[END_REF], the British Demos group (Demos, 2004), and the ETC group (ETC, 2003)-a non-governmental organization that previously has been successful in its fight against genetic engineering. There is growing concern among the scientists and supporters that nanotechnology could provide a target for intense debates about environmental and ethical consequences and dangers-analogous to those on biotechnology.

The Nanoforum, in cooperation with the European Commission, recently conducted an online survey to determine attitudes towards various aspects of nanoscience and nanotechnology development [START_REF] Malsch | Outcome of the Open Consultation on the European Strategy for Nanotechnology[END_REF]. The survey revealed that a majority of the respondents (75 percent) believe that health, safety, and environmental risks should be integrated early into research. Furthermore, 75 percent are convinced that Europe should take account of the societal impact of nanotechnology from an early stage and that more communication and dialogue is needed.

This raises the question of risk perception: do the critical voices affect public response? Or, in other words: how does the public think about the risks of nanotechnology?

The predominant framework for studying risk perception has been the "psychometric paradigm" (see [START_REF] Slovic | Facts and Fears: Understanding Perceived Risk[END_REF][START_REF] Slovic | Perception of Risk: Reflections on the Psychometric Paradigm[END_REF] which argues that risk perception (in contrast to expert risk assessments) can be explained by a number of "qualitative characteristics," such as voluntariness of risk, its controllability, knowledge about the risk, dread associated with risk, and so on. Recently, however, a trend to more diverse methodologies can be observed, among them qualitative studies (e.g. [START_REF] Smith | Risk Perception and the Presentation of Self: Reflections from Fieldwork on Risk[END_REF] and experimental designs [START_REF] Corbett | Testing Public (Un)Certainty of Science: Media Representations of Global Warming[END_REF].

This paper reports an experimental study, in which risk perception is studied with regard to a specific aspect: how do variations in the framing of risk issues influence risk perceptions of an emerging technology that is still largely unknown to the public?

Research on the public perception of nanotechnology

Research on risk perception of nanotechnology is at its very beginning. The few studies available so far on this issue are (with one exception) all surveys, looking at the public perception of the risks and benefits of nanotechnology or at knowledge about nanotechnology. These surveys reveal, not surprisingly, that the public's knowledge about nanotechnology is quite low. For instance, in 2004 a representative US phone survey found that about 80 percent of the respondents had heard "little" or "nothing" about nanotechnology [START_REF] Cobb | Public Perceptions about Nanotechnology: Risks, Benefits and Trust[END_REF]. Another US telephone survey yielded a similar result [START_REF] Scheufele | The Public and Nanotechnology: How Citizens Make Sense of Emerging Technologies[END_REF], as did a representative survey in Germany [START_REF] Passion | Wissen und Einstellungen zur Nanotechnologie[END_REF].

Despite the admittedly low levels of knowledge about nanotechnology, the survey results also indicate that public perception of nanotechnology is more positive than negative. In the United States, for instance, [START_REF] Bainbridge | Public Attitudes toward Nanotechnology[END_REF] conducted an Internet survey (N = 3909), indicating that only 9 percent of the participants agreed with the statement: "Our most powerful 21st-century technologies-robotics, genetic engineering, and nanotechnology-are threatening to make humans an endangered species."

The phone survey by [START_REF] Cobb | Public Perceptions about Nanotechnology: Risks, Benefits and Trust[END_REF] found that about 40 percent of the respondents thought that nanotechnology would produce more benefits than risks, 38 percent considered risks and benefits to be about equal, and only 22 percent said risks would outweigh the benefits. This study also revealed a number of interesting associations between the perception of nanotechnology and the respondents' views of science and their feelings towards nanotechnology. It turned out that the more positive the respondents' thoughts about science, the more they tended to see the benefits of nanotechnology outweighing the risks. Also, a majority of the respondents (70 percent) felt "very" or "somewhat" hopeful about nanotechnology, and only a minority (20 percent) expressed worry. Interestingly, about 60 percent of the respondents had "not much trust" in the ability or willingness of business leaders of the nanotechnology industry to minimize risks to humans.

Although a study by [START_REF] Gaskell | Imagining Nanotechnology: Cultural Support for Technological Innovation in Europe and the United States[END_REF] suggests that Europeans are more skeptical about the potential benefits of nanotechnology than people in the United States are, surveys in Britain (BMRB, 2004) and Germany [START_REF] Passion | Wissen und Einstellungen zur Nanotechnologie[END_REF] find that the public sees little risk in nanotechnology.

Of course, one has to be careful in drawing too strong conclusions from the few available studies on public perception of nanotechnology. In addition, at least some studies may suffer from methodological limitations, such as low response rates or questionable representativeness of sampling in a Web survey. Bearing these caveats in mind, one can summarize the results of these studies in saying that, in general, they paint a favorable picture of the public perception of nanotechnology: in the eyes of the public the benefits outweigh the risks. But what determines these perceptions? The low level of the public's knowledge about nanotechnology suggests that they are not based on facts. Rather, one can speculate that feelings about nanotechnology and, indeed, more general attitudes towards science and technology determine these perceptions.

This speculation is supported by the results of a regression analysis that Cobb and Macoubrie (2004) performed in their above-mentioned study. Risk versus benefit ratings were regressed on 14 variables which included socio-demographic aspects (e.g. gender, age) and several attitudinal and knowledge related items. In this analysis "hope" and "worry"together with the view of science-were the strongest predictors for perceptions of risks versus benefits, while other variables such as knowledge or "trust in business leaders" or socio-demographic factors such as gender or age were of minor importance.

An experimental study by [START_REF] Cobb | Framing Effects on Public Opinion about Nanotechnology[END_REF] analyzed how risk judgments and emotions about nanotechnology are influenced by how this technology is framed. He showed-among othersthat characterizing nanotechnology as associated with health risks or with multiple economic and environmental risks resulted in a higher proportion of respondents who agreed with the statement "that risks will outweigh the benefits." However, when nanotechnology was framed negatively without mentioning specific risks he found no effect. Conversely, framing nanotechnology in terms of (multiple) benefits resulted in a larger proportion of respondents agreeing with "benefits will outweigh the risks."

Hypotheses

Two hypotheses are tested in this experiment. Both are derived from research on framing effects in behavioral decision-making which have been shown in numerous studies (see [START_REF] Kühberger | The Influence of Framing on Risky Decisions: A Meta-analysis[END_REF]or Levin et al., 1998 for reviews). Tversky and Kahneman (1981: 453) defined a decision frame as "the decision-maker's conception of acts, outcomes and contingencies associated with a particular choice. The frame that a decision-maker adopts is controlled partly by the formulation of the problem and partly by the norms, habits, and personal characteristics of the decision maker." However, framing is not limited to the classical problem of describing options for decision-making in terms of loss and gain [START_REF] Tversky | The Framing of Decisions and the Psychology of Choice[END_REF][START_REF] Mcneil | On the Elicitation of Preferences for Alternative Therapies[END_REF], but is also effective in elucidating the different "emotional coloring" of risk problems [START_REF] Johnson | Affect, Generalization, and the Perception of Risk[END_REF][START_REF] Sandman | Agency Communication, Community Outrage, and Perception of Risk: Three Simulation Experiments[END_REF]. In this more general sense framing refers to the specific problem perspective that is induced through the description of the problem.

Hypothesis 1: Risk perception of nanotechnology is influenced by its benefit perception

We expect that providing information about different types of nanotechnology benefits will influence risk perception. Specifically we expect that applications of nanotechnology that provide medical or environmental benefits will receive lower risk judgments than applications for which the benefits are defined purely by economics.

Surveys on risk perception have observed an inverse relationship between risk and benefit perception, that is the higher the perceived benefits the lower the perceived risk and vice versa (e.g. [START_REF] Alhakami | A Psychological Study of the Inverse Relationships between Perceived Risk and Perceived Benefit[END_REF][START_REF] Fischhoff | How Safe is Safe Enough? A Psychometric Study of Attitudes toward Technological Risks and Benefits[END_REF][START_REF] Harding | Characterising the Perceived Risks and Benefits of Some Health Issues[END_REF]. Moreover, experimental studies found that manipulating information about the benefits of a technology can even change its risk perception and vice versa [START_REF] Finucane | The Affect Heuristic in Judgments of Risks and Benefits[END_REF]. For the field of biotechnology, a number of studies have shown that risk and benefit perception differ for "red" biotechnology (dealing with animals, e.g. animal cloning) and "green" biotechnology (dealing with plants, e.g. introduced pesticide resistance) [START_REF] Gaskell | Europeans and Biotechnology in[END_REF][START_REF] Savadori | Expert and Public Perception of Risk from Biotechnology[END_REF][START_REF] Sjöberg | Gene Technology in the Eyes of the Public and Experts: Moral Opinions, Attitudes and Risk Perception[END_REF]. Results from [START_REF] Gaskell | GM Foods and the Misperception of Risk Perception[END_REF] suggest that the public's rejection of green biotechnology might be due to the low benefits that the public sees for this technology. Characterizing nanotechnology in terms of different types of benefits is an example of what [START_REF] Cobb | Framing Effects on Public Opinion about Nanotechnology[END_REF] has referred to as issue framing.

Hypothesis 2: Risk perception of nanotechnology is influenced by the social context in which nanotechnology is embedded

In previous experiments we and our colleagues have shown that identical risk information can provoke different risk judgments, depending on the "emotional coloring" of the social context in which the risk event is embedded [START_REF] Spangenberg | Risikostories und Risikobewertung. Deutschland und Bulgarien im Vergleich[END_REF][START_REF] Wiedemann | Understanding Amplification of Complex Risk Issues: The Risk Story Model Applied to the EMF Case[END_REF]. In these experiments, two versions of a risk story have been constructed that describe an objectively identical damage event. One version is meant to evoke outrage, while the other version to evoke leniency. On average, respondents in the outrage condition yielded (statistically significant) higher risk ratings than the respondents in the leniency condition.

The "social context" information used to provoke outrage or leniency was related to characteristics of the parties (i.e. the actors) responsible for the risk situation. For instance-in the case of outrage-being a large multinational enterprise not caring about the worries of those affected by the risk, versus-in the case of leniency-being a small family business listening to the concerns of the people. We expect that the social characteristics of the enterprises involved in the development of nanotechnology will influence risk perception. If these characteristics are given a negative connotation, for instance as described above, this will amplify risk perception. If the connotation is positive, risk perceptions will be attenuated.

This type of framing is different from the issue framing used in hypothesis 1. In this case it is the information about the social context of nanotechnology which is changed, and not the information about the issue itself. We therefore refer to this type of framing as context framing.

Method

Study design

A 3 × 2 factorial design was used for this experiment. The first factor addresses the benefits of nanotechnology: 1) health benefits, 2) economic benefits, and 3) environmental benefits. The second factor varies the characteristics of the enterprises that benefit from nanotechnology: 1) large multinational enterprises, and 2) small and medium-sized enterprises.

Sample

The experiment was conducted with an ad hoc sample of students from the University of Innsbruck (Austria) and staff from the Center of Natural Hazard Management (AlpS) in Innsbruck. A total of N = 194 respondents participated in the experiment (female: 79 percent, male: 21 percent). Median age is 21 years (range: 19-60). The highest educational attainment of the participants was: university-entrance diploma (Matura): 87 percent, university degree: 13 percent. The experiment was carried out in March 2005 and took place in the seminar rooms of the University of Innsbruck and at the Center of Natural Hazard Management Innsbruck.

Materials

Six different short written descriptions of nanotechnology served as experimental stimuli. These comprised a basic text (given to all participants) and a combination of text modules for each variation of the two factors.

First, each participant received a basic text that gave a brief, factual introduction to nanotechnology:

Nanotechnology is defined as technology that deals with dimensions on the order of onebillionth of a meter. In contrast, the thickness of a human hair is about 80,000 nanometers. Nanotechnology is focussed on creating and applying materials at a nanoscale dimension, i.e. at the scale of one to ten atoms in diameter. At the same time, the tools needed for being able to directly access and manipulate single atoms and molecules are being developed. Subsequently, each participant received one of the six different combinations of text modules representing the 3 × 2 variations of the experimental factors. Participants were randomly assigned to the experimental conditions. Table 1 presents the text modules "benefits" and "characteristics of the enterprise."

After reading the text, the participants had to assess the likelihood of six risk scenarios (see Table 2). The scenarios were taken from the political discussion about possible risks of nanotechnology (cf. [START_REF] Van Est | Om het kleine te waarderen … Een schets van nanotechnologie publiek debat, toepassingsgebieden en maatschappelijke aandachtspunten[END_REF]. These scenarios address health and environmental hazards (scenarios A and B), "science-fiction" risks (scenarios C, D, E) and unknown risk potentials (scenario F). For assessing the probability of the scenarios, a 100-point rating scale with endpoints labeled "cannot happen" (0 percent probability) and "will happen" (100 percent probability) was given to the participants.

Results

Figure 1 shows the probability assessments for the six risk scenarios. In this box plot, the middle 50 percent of the distribution (from the 25th percentile to 75th percentile) are shown as a box, while the vertical lines delineated by cross lines at the ends (the "whiskers") show the distance from the end of the box to the largest and smallest observed values that are less than 1.5 box lengths from either end of the box. The dots and asterisks denote individual judgments that lie outside of this interval (outliers and extreme values). The solid horizontal line inside the box is the median value. The variability in the assessments is conspicuous, both within and between scenarios. The average probability assessments are highest for the scenario "unknown risks," and lowest for the three "science-fiction" scenarios, with the health and environmental risk scenarios situated in between.

It is clear from Figure 1 that the distribution of the probability assessments for the risk scenarios is quite skewed. To further investigate this, non-parametric tests (Kruskall-Wallis and Mann-Whitney U) were used for the analyses of the experimental effects. For each risk scenario a separate test was conducted.

Figure 2 shows the probability assessments of the scenarios for the three types of nanotechnology benefits (factor 1: issue framing). It reveals noticeable differences between the probability assessments for scenarios A, B and F with regard to the three types of nan-

Experimental factor

Text modules Benefits "Health benefits" Nano-products are increasingly being used in medicine. It is estimated that by 2010 almost half of all pharmaceutical products will be based on nanotechnology.

There are especially high hopes for the fight against cancer. "Economic benefits" Today, nanoparticles can already be found in sun lotion, cosmetics, textiles, tennis-rackets and -balls, computer displays, disinfectants, and bandages. This is, however, certainly just the beginning and economists expect the global market for nanotech products to rise to 900 million dollars in 2005. "Environmental benefits" Nanotechnology will enable the development of new materials, which will be of benefit to the environment and help to conserve energy.

Characteristics of "Multinational enterprise" the enterprise

Nanotechnology is primarily only a promising R&D technology for the large multinational companies, e.g. General Electric, IBM and Dupont. It will make the large multinational companies even more powerful. "Small and medium-sized enterprises" (SME) Nanotechnology offers especially for small and medium-sized companies an opportunity to enter the market and to establish themselves in competition against the large multinational companies.

Table 2. Risk scenarios

Scenario A If materials that are normally harmless are adapted to superfine nanoparticles, they will become toxic and harmful to people Scenario B

Nanoparticles will be distributed in the environment and substantially contribute to environmental damage Scenario C

Nanorobots-invisibly tiny robots-will get out of control and threaten the human race Scenario D Nanosystems will integrate into living organisms, and will lead to the demise of the human race Scenario E Nanotechnology will result in dangerous hybrids-part human, part machine Scenario F Nanotechnology can lead to as yet unknown risks that can harm humans and the environment otechnology benefits. However, these differences are not statistically significant (see Table 3), although at least for scenarios B and F the order of the (median) probability assessments for the three types of nanotechnology benefits corresponds to the order that was expected in hypothesis 1. Nevertheless, it is clear from these data that the first hypothesis-the risk judgments depend on the type of benefit associated with nanotechnologyis not supported. In contrast, factor 2 (context framing) yields statistically significant effects for five of the six scenarios (see Figure 3). And for three of these five significant results, the size of the effects is considerable. The differences between the characterization of the enterprise as multinational versus small or medium-sized are in the range of 10 percent to almost 30 percent. Table 4 gives the details of the statistical analysis.

Obviously, the characteristics of the enterprise benefiting from nanotechnology appear to affect the plausibility of risk scenarios. This result supports the second hypothesis. Risk judgments (in terms of plausibility of risk scenarios) are influenced by the social context in which nanotechnology is embedded. If small or medium-sized enterprises are portrayed to be the beneficiaries of nanotechnology, they receive lower probability assessments for five of the six risk scenarios.

Discussion

This experimental study investigates the effect of different types of framing on risk perception of nanotechnology. Different from most risk perception surveys, which typically ask for direct ratings of perceived risk, this study operationalizes risk perception in terms of probability assessments of given risk scenarios. This way of measurement was chosen, because the generally low level of public knowledge about nanotechnology at the present time renders the usefulness and logical sense of directly asking for risk judgments questionable.

The six different risk scenarios given to the participants receive quite different probability assessments. The highest assessments were given for the scenario F "unknown risks." Naturally, unknown risks can never be ruled out, but the high scores given for this scenario are striking and speak for negative expectations. However, if unknown risks are objectifiedin terms of risks for human health (scenario A) or the environment (scenario B)-the respective scenarios receive much lower probability assessments. In addition, the probability assessments become very low if scenarios are to be assessed which portray developments of nanotechnology that belong-quite apparently-to the realm of science fiction.

As well as the general perceptions of nanotechnology risks, two specific hypotheses were investigated in this study. The first hypothesis, which proposed an effect based on the type of benefits that nanotechnology provides (health, environmental, and economic) on probability assessments of the scenarios, is not supported by the data. In contrast to findings for other new technologies, e.g. biotechnology, in our study the different types of benefit did not affect risk perceptions. Of course, this is not to say that benefits do not play a role for the perception of nanotechnology. In fact, the experimental study by [START_REF] Cobb | Framing Effects on Public Opinion about Nanotechnology[END_REF] found a statistically significant effect of adding benefit information to an objective description of nanotechnology on the risk-benefit evaluation.

The second hypothesis proposed an effect of context framing, namely that the social context in which nanotechnology is embedded influences risk perception. Specifically, the effect of characterizing the enterprises that benefit from nanotechnology as large multinational versus small or medium-sized, was expected to lead to differences in perceived risk. This hypothesis is supported by the data. In the experiment, participants given the "large multinational enterprises" condition assessed the probability of five of the six scenarios much higher than participants given the "small or medium-sized enterprises" condition did. In a different context we have described this type of influence as "story information" [START_REF] Wiedemann | Understanding Amplification of Complex Risk Issues: The Risk Story Model Applied to the EMF Case[END_REF], as it does not address the risk per se but the characteristics of actors who are involved in the risk generating process-either as being responsible for the risk or as being a "victim" of the risk. The social characteristics of these actors (e.g. size of an enterprise) can influence risk perceptions and ultimately risk judgments, although these characteristics do not have any direct relationship to the risk. It can be speculated that such risk stories are engraved in the collective memory [START_REF] Toumey | Narratives for Nanotech: Anticipating Public Reaction to Nanotechnology[END_REF], so that they would be available as yardsticks for evaluation (in the sense of [START_REF] Hsee | Attribute Evaluability: Its Implications for Joint-Separate Evaluation Reversals and Beyond[END_REF]. This would explain why social characteristics of enterprises-though factually irrelevanthave such an impact on risk perception.

Figure 1 .Figure 2 .

 12 Figure 1. Box plot of the probability assessments for the six scenarios (scale: 0% to 100%).

Figure 3 .

 3 Figure 3. Median probability assessments for the factor "characteristics of the enterprise."

Schütz and Wiedemann :

 Wiedemann Risk perception of nanotechnology 377

Table 1 .

 1 Text modules used in the experiment

Table 3 .

 3 Effects of benefit of nanotechnology on the probability assessments of the risk scenarios (Kruskall-Wallis test)

	Scenario	χ²	d f	p
	(A) Toxic	2.7017	2	0.259
	(B) Environmental damage	0.4853	2	0.785
	(C) Nanorobots threaten	0.7314	2	0.694
	(D) Nanosystems assimilation	0.1517	2	0.927
	(E) Hybrid beings	0.0125	2	0.994
	(F) Unknown risks	5.4789	2	0.065

Table 4 .

 4 Effects of characteristics of the enterprises on the probability assessments of the risk scenarios (Mann-Whitney U test)

	Scenario	Mann-Whitney U	p
	(A) Toxic	3805.0	0.021
	(B) Environmental damage	3456.5	0.001
	(C) Nanorobots threaten	3903.0	0.042
	(D) Nanosystems assimilation	4013.5	0.095
	(E) Hybrid beings	3810.5	0.021
	(F) Unknown risks	3514.5	0.002

Public Understanding of Science 17 (3)

Public Understanding of Science 17 (3)

Acknowledgements

We thank the students of the Psychology Department at the University of Innsbruck as well as the staff members of AlpS, Innsbruck, for their willingness to participate in our experiment.

We also wish to thank two anonymous reviewers for their helpful comments.

Authors

Peter Wiedemann, Ph.D., is the director of the program group MUT (Humans, Environment and Technology) at the Research Center Juelich, Germany. His research focuses on bridging the gap between risk perception research and risk communication on the one side and risk analysis and management on the other side. He is currently performing research in comparative risk assessment, uncertainty analysis, and evidence assessment to provide a basis of sound science for the application of the precautionary principle. Correspondence: Research Center Jülich, Program Group MUT, 52425 Jülich, Germany; e-mail: P.Wiedemann@fz-juelich.de Holger Schütz is a senior researcher at the program group MUT. His research interests center on risk perception and risk communication.