Research

Social Status

I primarily study social status. The pursuit of social status and modification of behavior according to status differences are core elements of human behavior, as they are for other group-living mammals. Research topics of mine include:

1. how women and men acquire status

2. how status affects health and reproduction

3. how the social networks and production systems of communities affect the extent of status inequality

Most of my empirical work on these topics has resulted from extensive fieldwork among the Tsimane', who are forager-horticulturalists in Amazonian Bolivia. Tsimane' communities are relatively egalitarian, lack significant material wealth, are largely ethnically homogeneous, and are small in size. These attributes make status hierarchy in their society useful for making inferences about the evolution of status hierarchy in ancestral human societies, prior to social stratification by wealth class and ethnicity. However, the Tsimane' are not "living fossils". Tsimane' society has long been influenced by colonists and the Bolivian state, and recently accelerated participation by the Tsimane' in the market economy is revealing the mechanisms which can exacerbate status inequality.

See here for talks I have given on social status:

• Coalitions, conflict and status dynamics among the Tsimane'

• Market integration and changes to status inequality among the Tsimane' 

• Tedx talk on evolution of human status hierarchy

And here is an interview on social status for the Radius of Reason podcast:

• Decoding human status

Leadership and Collective Action

Models of collective action infrequently account for differences across individuals beyond a limited set of strategies, ignoring variation in endowment (e.g. physical condition, wealth, knowledge, personality, social support) or expected gains from cooperation . This variation can catalyze collective action via the emergence of leader-follower relationships. Leadership is the domain of social status that occupies most of my attention among the Tsimane', particularly informal political leadership in the context of community representation, coordination of meetings, and dispute resolution.  I have edited two special issues related to leadership evolution, one with Luke Glowacki and Sergey Gavrilets at Philosophical Transactions of the Royal Society B, and the other with Mark Van Vugt at The Leadership Quarterly.

See here for an interview on leadership on The Dissenter podcast:

• Leadership and Hierarchy from an Evolutionary Perspective

And on the Modern Wisdom podcast:

• How did Human Leadership Evolve?

Fatherhood 

Humans are unique among primates in many facets of our social organization. This includes multi-male, multi-female communities in which mating is not promiscuous but rather tends to be concentrated within pair-bonds.  Fathers often provide a significant amount of support to their families, in coordination with mothers. I am interested in whether fathers have unique effects on children's social development, such as play with peers, and how father relationships with children vary cross-culturally. With Tanya Broesch of Simon Fraser University, I am studying father relationships with their children in the Tsimane' and on Tanna Island, Vanuatu.

Personality

Personality psychology has been dominated by descriptive models like the Big Five. With colleagues, I have  found that the Big Five is a poor fit to personality variation among the Tsimane'. We have subsequently developed and tested an explanatory model of personality variation in humans: the "socioecological complexity hypothesis" .

Morality

With the Culture and the Mind project,  I have investigated moral decision-making across a number of traditional societies including the Tsimane'. We find a general tendency for harms to be judged less punishable when unintentional, sanctioned by an authority, or involving people in the past or far away. However, there is significant variation cross-culturally and across types of harm. See here for my description of these results.