“…A review of literature shows mixed findings with regard to the question of whether groups of friends perform better or worse than groups of acquaintances. Whereas some studies have documented a positive effect of friendship on group performance (e.g., Harrison, Mohammed, McGrath, Florey, & Vanderstoep, 2003; Jehn & Shah, 1997; Shah & Jehn, 1993), other studies have not documented performance benefits of friendship groups (e.g., Andersson & Rönnberg, 1996; Nibler & Harris, 2003; Peker & Tekcan, 2009; Swenson & Strough, 2008).…”