FABBRO:
Lack some most important structural prerequisites for engaging in war; Little or no surplus that can be used to develop military/political org, strong leadership
Werner Levi:
Though may be aggressive to some extent, but not enough to kill others, maybe environmental factors or compassion innate
Raymond kelly:
Social substitutability;
Warless societies are unsegmented societies, vengeance is directed only at the individual responsible, not at other members
Behavioral psychologists: Aggression can be modified through the learning of peaceful or cooperative responses; many societies have “learned” to be nonaggressive.