Rats reared with playful peers during the juvenile period have a modified prefrontal cortex and improved executive functions, whereas ones reared with less playful partners, such as an adult, do not. It has been hypothesized that peer-peer play fighting creates unique experiences that tax executive functions and so influence the refinement of the prefrontal cortex. The present study compares the rough-and-tumble play of juveniles interacting with another peer with that of juveniles interacting with an adult. The juveniles interacting with adults engage in as much play as those that interact with juveniles. However, they experience fewer attacks from their adult partners and experience fewer bouts of close-quarter wrestling. Moreover, the juveniles in these juvenile-adult pairs experience fewer opportunities to perform role reversals in which the attacker becomes the defender. These findings are consistent with the hypothesis that the turn taking typical of the play fighting with peers is critical for the development of executive functions. © 2017 International Journal of Comparative Psychology.