Risk and reciprocity in Meriam food sharing

Foragers who do not practice food storage might adapt to fluctuating food supplies by sharing surplus resources in times of plenty with the expectation of receiving in times of shortfall. In this paper, we derive a number of predictions from this perspective, which we term the risk reduction reciprocity (RRR) model, and test these with ethnographic data on foraging (fishing, shellfish collecting, and turtle hunting) among the Meriam (Torres Strait, Australia). While the size of a harvest strongly predicts that a portion will be shared beyond the household of the acquirer, the effects of key measures of foraging risk (e.g., failure rate) are comparatively weak: Harvests from high-risk hunt types are usually shared more often than those from low-risk hunt types in the same macropatch, but increases in risk overall do not accurately predict increases in the probability of sharing. In addition, free-riders (those who take shares but do not reciprocate) are not discriminated against, those who share more often and more generously do not predictably receive more, and most sharing relationships between households (over 80%) involve one-way flows.