Japanese toddlers prefer the scent of soy sauce to that of honey with a sweet drink

Subjective taste intensity in adults is affected by the scent of food. Previous studies have shown that children, compared with adults, prefer sweet-tasting foods, as well as foods with a familiar smell. However, how taste smell congruency and smell familiarity develop in early toddlerhood is still unclear. Here, we examined the effects of the odours of soy sauce, one of the most familiar foods in Japan, and honey, which is a sweet gustatory stimulus but unfamiliar to younger Japanese toddlers, by comparing the sugared water consumption of toddlers under different odour conditions. Forty-seven younger (N = 23, age range = 378-726 days) and older (N = 24, age range = 731-1001 days) Japanese toddlers completed the experiment. For each condition, the toddlers were handed a two-handled mug with a straw filled with sugared water. The test liquid was dropped onto a cotton puff packed into a small basket attached to the mug to present odour stimuli. Our results showed that the consumption of sugared water was significantly higher for the soy sauce condition than the honey condition. This result suggests that familiar food odours, such as soy sauce for the Japanese population, may enhance beverage preference even in toddlerhood.