The interplay between the expression of individual behaviour and the social environment is of fundamental importance to our understanding of animal behaviour. For instance, most individual behavioural traits, such as aggression, courtship, or vigilance, are a direct consequence of the social environment or social competition. These traits however, are often studied in isolation and as a result, relatively few studies have examined the role that social context plays in developing and modifying individual behavioural differences. Here we examine this question from two different perspectives; the effect of social context on individuals, and the effects of individuals on group-level behaviour. We find social context has a significant effect on the behaviour of juvenile damselfish and that this effect is lessened in adults, suggesting younger individuals are more likely to conform to their respective social groups. Additionally, we find group behaviour varies as a result of both the age and personality of group members, thus suggesting both conformity and individuality interact to determine group behaviour and decision-making. By discussing these results in the context of both collective behaviour/decision-making and current animal personality research, this study sheds new light on how and when individuals may adjust their behaviour in groups.