The present research focuses on the study of behavioral effects of non-conscious activation of categories among outgroup (young people) and ingroup members (elderly people). Specifically, non-conscious activation of labels that designate the same group, but with different valence (old vs. elderly), showed an effect on a behavior not directly related to interaction with elderly. The first study with young individuals (N= 62) shows that, after non-conscious activation of a negative label (old), participants displayed longer RTs in the first phase of the task than in the case of positive label (elderly) priming. The second study (N= 40), performed with elderly people, shows a similar result, after non-conscious activation of a negative label (old), elderly people showed longer RTs in the first phase of the task, compared with the group in the non-conscious positive label activation condition. Results concerning the theoretical and practical implications are discussed.