Leaders in non-human societies wield more power over followers than ours do, according to new findings published in Trends in Ecology & Evolution. Though, like humans, most – but not all – animal leaders rise to the top based on individual achievement.
The phenomenon of leadership and collective action is common in social species. Bottlenose dolphin alliances swim in pods with dozens of members, zebra harems travel together in herds, and meerkats live in clans of about 20 extended family members, for example. Yet, what all these leaders have in common – with each other and with humans – hasn’t been studied intensively. To investigate, Jennifer Smith of Mills College in California and colleagues reviewed previous studies on leadership in four areas: movement, food acquisition, within-group conflict mediation, and between-group interactions.
They compared 16 different small-scale societies, including eight human groups from Africa and North and South America and eight non-human groups: African elephants, bottlenose dolphins, chimps, lions, meerkats, plains zebras, spotted hyenas, and white-faced capuchins. Variation in leadership can be measured in a few different ways, such as how one becomes a leader, how widely leadership is shared among others, how much power is exerted, how likely they are to gain or lose followers, and how much the leaders of one domain (like movement) also lead in another (like conflict resolution).
Across species, leadership is generally achieved as individuals age and gain experience. One notable animal exception is the spotted hyena, where rank is inherited from the mother.
However, compared to people, animal leaders exert more power over their followers – though this is achieved through communication and other passive ways, rarely coercion. Additionally, leadership among non-human mammals is more concentrated and domain-general: Those who resolve within-group conflicts, might also decide between-group interactions, for example. Humans, on the other hand, tend to take on specialized roles within our various groups.
Similarities between human and other mammal leaders likely reflect the evolution of shared cognitive mechanisms governing dominance-subordination, alliance formation, and decision-making, the team writes.
