Social inclusion increases over early childhood and is influenced by others’ group membership.

This study examined preschoolers' social inclusion-the active involvement of new partners into social interactions-in different intergroup contexts. Using an interactive paradigm, 3- to 5-year-old German children played a ball-tossing game with 2 puppets in which 1 puppet initiated the game with the child and another approached the game. In Study 1 (N = 144), the initiator was from an ingroup while an outgroup puppet approached the game...