Hominids, coalitions, and weapons: Not vehicles

Pace Wilson & Sober, group selection has not won over biology. However, the combination of fission/fusion organization (favoring coalition formation and relatively complex tactical behavior) with weapons (which in conjunction with group and/or ambush attacks greatly reduce the costs to actors of lethal inter- and intragroup aggression) create circumstances which may well have favored group selection in hominid evolution.