Social attitudes differentially modulate imitation in adolescents and adults

Previous studies have demonstrated a bidirectional relationship between social attitudes and imitation in adults: pro-social attitudes promote imitation, and imitation further increases positive social attitudes. Social attitudes and the social brain are developing throughout the adolescent years. Thus, the aim of this study was to test whether pro-social attitudes promote imitation in an Adolescent Group to the same extent as in an Adult Group. Participants were primed with pro-social or non-social words in a Scrambled Sentence Priming task. They then completed an Imitation task wherein participants were required to perform a lift action with either the index or middle finger, whilst observing either a compatible action (e.g. index finger response and observed index finger lift) or an incompatible action (e.g. index finger response and observed middle finger lift). In an Effector Priming control condition, observed fingers remained stationary but a semi-transparent green mask was added to either the compatible or incompatible finger. The magnitude of the Imitation Effect and Effector Priming Effect was calculated by subtracting reaction times on compatible trials from those on incompatible trials. In the Adult Group, social priming specifically modulated the Imitation Effect: pro-social priming produced a larger Imitation Effect but did not modulate the Effector Priming Effect. In adolescents, however, no effect of social priming was seen on either the Imitation or Effector Priming measures. We consider possible explanations for these results including the immature development of social brain regions and reduced experience of the relationship between social attitudes and imitation in adolescence.