Eileen Kennedy-Moore describes three key ingredients of children's friendship formation: (1) openness, (2) similarity, and (3) shared fun.
and others, Kennedy-Moore outlines developmental stages in children's friendship, reflecting an increasing capacity to understand others' perspectives: "I Want It My Way", "What's In It For Me?
They gain the ability to empathize with their friends, and enjoy playing in groups.
They also experience peer rejection as they move through the middle childhood years.
Additionally, older adults in declining health who remain in contact with friends show improved psychological well-being.
Children with attention deficit hyperactivity disorder (ADHD) may have difficulty forming and maintaining friendships, due to a limited ability to build social skills through observational learning, difficulties attending to social cues, and because of the social impacts of impulsive behavior and a greater tendency to engage in behavior that may be seen as disruptive by their peers.
In a 2007 review, no treatment was identified which effectively address peer functioning in children with ADHD, and treatments which addressed other aspects of the disorder were not found to eliminate issues related to peer functioning.