The aim of this study was to focus on the role of gender-related differences in collaborative play, by examining properties of play as a complex system, and by using micro genetic analysis techniques. A complex dynamic systems model of dyadic play was used to make predictions with regard to duration and number of contact-episodes during play of same-sex dyads, both on the micro- (i.e., per individual session), meso- (i.e., in smoothed data), and macro time scale (i.e., the change over six consecutive play sessions). The empirical data came from a study that examined the collaborative play skills of children who experienced six twenty minute play sessions within a three week period of time. Monte Carlo permutation analyses were used to compa...