Fear not a factor in half of all nightmares, study finds Researchers collected nearly 10,000 dream reports and analysed 253 nightmares and 431 bad dreams from 572 respondents. The results found that nightmares were significantly more likely to contain themes of physical aggression, being chased, evil forces and accidents, whereas themes of interpersonal conflicts were significantly more frequent in bad dreams. The researchers wrote: "the present findings show that physical threats are more likely to characterise nightmares whereas psychological threats, including threats to self-esteem, are more prominent in bad dreams." Nightmares were rated by participants as being significantly more intense than were bad dreams. Nightmares were also classed as "significantly more bizarre" (more unlike everyday life) than bad dreams. Participants noted the cause of their awakening in more than a third of nightmares reported. The most frequent explanations included an immediate threat, the intensity of the emotions experienced, and an intentional awakening from the nightmare. The research also found that men and women tend to have different dreams. Men were "significantly" more likely to report themes involving disaster or calamity as well as insects while women's dreams were more likely to feature interpersonal conflicts. According to the researchers the study revealed that triggers for nightmares are often caused by external events but that the first portion of bad dreams can be relatively uneventful. However they also concluded that 22 per cent of all nightmares and 38 per cent of bad dreams contained either a partially positive or entirely positive outcome such as finally being saved or rescued. The lead author of the survey, Dr Geneviève Robert, said: "Death, health concerns and threats are common themes in nightmares, but it would be wrong to think that they characterise all nightmares. Sometimes, it is the feeling of a threat or an ominous atmosphere that causes the person to awaken. I'm thinking of one narrative, in which the person saw an owl on a branch and was absolutely terrified.