From attitude to identity? A field experiment on attitude activation, identity formation, and meat reduction

The reciprocal relationship between a person's identity and behaviour is well documented, but there is little research on the identity-formation process. We propose that self-perceptions generated from changed behaviour are not transformed into a new identity right away. However, identity-consistent behaviour increases the strength and positive valence of the attitude towards the behaviour. With repeated behaviour, this attitude becomes increasingly self-defining and therefore increasingly likely to be transformed into an identity. This hypothesis was tested in a longitudinal field experiment focusing on flexitarian and vegetarian identities, where participants (605 9th and 10th graders in Denmark) were randomly allocated to two different treatments, involving different combinations of a strong and a weak "nudge" to eat more vegetarian food. Vegetarian meals (VM) were an option in both groups, but in the first group, VM were the default for four weeks, followed by four weeks where VM was an option, but not the default. In the second group, the order of the two conditions was reversed. As expected, significantly more participants chose vegetarian when it was the default and the frequency of VM affected flexitarian and vegetarian identity. Attitudes fully mediated the impact of behaviour on flexitarian identity over the eight-week study. Most of the effect appeared in the first four weeks. Hence, it appears that the self-perception process starts with attitude change before it leads to the adoption of a new identity. These findings provide new insights for the promotion of reduced meat-eating and other pro-environmental behaviours.