The IAT as a predictor of food choice: The case of fruits versus snacks

One of the issues concerning the application of implicit measures like the IAT is whether they can be successfully applied to consumer choices. The empirical evidence of the predictive validity of the IAT so far has been mixed, both at the level of eating habits and of specific behavioural food choices. Moreover, whereas the predictive validity of the IAT has been tested in a number of studies, its incremental validity has not been studied as thoroughly. In this contribution, four studies, run at different points in time and analysed as a single sample (N = 399), tested the predictive and incremental validity of an IAT of attitudes towards fruits versus snacks on the choice of a fruit or a snack at the end of the experimental session. Specifically, an additive pattern in which both implicit and explicit measures predict independently, and an interactive one in which implicit and explicit measures predict interactively, were tested for the prediction of the behavioural preference towards snacks or fruits. The results showed that the IAT has both predictive and incremental validity, over and above the significant prediction provided by explicit measures for behavioural food choice. Furthermore, no interaction effect between implicit and explicit measures in the behavioural prediction was obtained, supporting the additive rather than the interactive pattern. Finally, only the explicit attitude towards snacks predicted behavioural choice whereas the explicit attitude towards fruits did not. This result indirectly suggests that a single target IAT might be fruitfully adopted in future research.