Group decisions in humans and animals: a survey --- Larissa Conradt, Christian List 2008:

Generally, the assignment of weights can lie anywhere between an equal weight for all group members ("egalitarian", "equally shared" or "dispersed" decision making) and a concentration on one individual ("dictatorial", "unshared" or "concentrated" decision making). Intermediate cases, in which some group members (e.g. the highest ranking ones), but not all, contribute to the group decision, are particularly common in practice. Examples in the social sciences are oligarchic or meritocratic decisions. However, even in democracies, at least some group members are typically excluded from group decisions (e.g. children, adolescents and non-citizens). While truly equally shared decisions are very rare in animals, decisions ranging from nearly equally shared to completely unshared ones have been reported in animals from insects to primates.