Playing together: Children will often play next to each other even if they are not involved in the same game.
By the time your child reaches age four, he is likely to be able to play with other children in an interactive and sustained way. The members of your child’s group may change rapidly and there may not be an allegiance to a special friend at this stage, though girls are more likely than boys to pair off with a particular friend. Although children may tease peers of the opposite sex, gender is not usually a criterion for selecting friends- neither is race.
By age five, children tend to select a single playmate, but their play is not necessarily interactive: children often “parallel play,” occupying the same area but doing different things. The most frequent grouping is two children of the same gender, but even at this age, gender is not a major criterion for making new friends.
Although group play demands some cooperation from children, this is quite superficial, since children can often play with their own ends in mind and have little concern for the group as a whole.