From social inhibition in childhood to social facilitation in adulthood: How social presence systematically enhances the predominant response strategy in cognitive tasks

This study investigated the developmental trajectory of social facilitation and inhibition across 207 participants aged 8–22 in numerosity and phonological comparison tasks. Tested alone or in coaction with a familiar age-matched partner, younger participants exhibited social inhibition on reaction times (RT), while a shift toward facilitation occurred around ages 13–14. Analysis of individual RT distributions revealed that social presence modulated predominant response strategies: younger participants used slower, reactive strategies, while older participants employed faster, anticipative ones. By enhancing the strategy predominating in each age group, social presence led to social inhibition in children and early adolescents, but social facilitation in mid-adolescents and adults. There was no influence of the partner’s presence on accuracy, suggesting that while social presence modulated this predominant response, the presence of a partner did not impact the task performance in terms of correct answers. Together, these findings challenge Zajonc’s “dominant response” theory, suggesting that social presence affects overall decision-making strategies.