The present study examined Japanese children's and adults' awareness of the effects of psychological taste experiences on biological processes such as growth and illness. Studies 1 and 2 showed the following: (1) preschoolers tended to assume that good-tasting experiences would make one grow taller and gain more weight, while adults seldom accepted such ideas. Concerning illness, participants in all age groups were reluctant to accept the effects of taste experiences. (2) Process-dependent awareness (i.e., effects of psychological factors were assumed to depend on biological processes) was observed not only among young children, but also in older children and adults. Compared with younger children, adults' responses were more process sensitive. (3) When adults explained why they assumed that different taste experiences would lead to different bodily states, they often relied on vitalistic causality. The use of vitalistic concepts was uncommon among children. Finally, (4) Japanese participants seem to be more likely than Americans to assume that bad-tasting experiences would make them non-resistant to a cold.