ferent from each other. In other words, it is difficult to explain these cross-cultural differences simply in terms of the differentiation between Eastern and Western countries. In addition to cultural difference, differences in other domains, such as geographic locations, climates, agriculture, may also play an important role in the formation of crossmodal associations between taste/flavors and visual features (see also Wan et al., 2014, 2015). That being said, it should also be borne in mind that other factors, such as age, gender, travel (which likely means more exposure other cultures), cooking experience, might also vary between participants within a group or cross groups (see also Levitan et al., 2014). It is also possible that, when seeing a taste term, different people might imagine different foods/flavors due to the specific associations they have to each specific taste (see also Majid and Burenhult, 2014). For example, when seeing the word bitter, the Chinese might think of strong tea or traditional Chinese medicine, whereas people from the USA might think of black coffee. The formation of crossmodal associations with taste might be very complicated, and vary from culture to culture, individual to individual.
It should also be noted that two of the shapes in the present study (i.e., named as the “blob” and “asymmetric star”) were very similar to (if not identical to) the round and sharp shapes which were used to elicit the Bouba–Kiki effect (Köhler, 1929; Marks, 1978; Ramachandran and Hubbard, 2001; Bremner et al., 2013). Previous studies have revealed some cross-cultural difference in the crossmodal correspondences between sharp/round shapes and certain tastes/flavors, such as the carbonation of the water (Gallace et al., 2011; Ngo et al., 2012; Bremner et al., 2013) and the bitterness of chocolate (Ngo et al., 2011; Bremner et al., 2013). However, we did not find significant effects of culture on the taste-patterns for these two shapes, which is inconsistent with the findings of previous studies. Martino and Marks (2001) suggested that the crossmodal associations in weak synesthesia are systematic and contextual, whereas those in strong synesthesia are systematic and absolute (see also Marks, 2013; Marks and Mulvenna, 2013).
Therefore, one possible reason for the discrepancy between our results and the results of previous studies might be that these taste-shape correspondences depend to some degree on the particular shapes that are presented and on the total number of shapes presented. For example, it was the marketers of last couple of decades who taught the Western world about the associations between the limpid electric blue and the sweet raspberry taste/flavor (Shankar et al., 2010). A similar discrepancy has also been observed in the literature of odor-shape correspondences. On one hand, Hanson-Vaux et al. (2013) had their participants match 20 odors with a pair of shapes which were often used to elicit the Bouba–Kiki effect. Their results revealed that the lemon and pepper odors were associated with the angular shape, whereas the raspberry and vanilla odors were associated with the round shape, indicating a Bouba–Kiki effect in the odor-shape associations. On the other hand, Seo et al. (2010) asked their participants to match eight odors with 19 irregular shapes (which were referred to as abstract symbols in their paper). Interestingly, the results revealed that pleasant odors were associated with circular or curved shapes, whereas unpleasant shapes were associated with square or angular shapes instead. It is difficult to directly compare the findings in these two studies, as different shapes were used. However, it should be noted that when a large range of varied shapes were used, the more global features (e.g., whether a shape is circular or angular) influences which odors were associated with them. Similarly, when only a blob and an asymmetric star shape, or two categories of round and sharp shapes (see Deroy and Valentin, 2011), were presented, the sharp vs. round difference between them may be sign