| Abstract: |
Explaining how cooperation evolves is a major research programme in the
biological and social sciences. In this study we tested evolutionary theories
of human cooperation in a real-world social dilemma: joint liability
microfinance, in which groups of borrowers must cooperate to successfully
repay a shared loan. We used pre-registered Bayesian multilevel models to
estimate meta-analytic associations between loan repayment and proxies of four
evolutionary mechanisms proposed to support cooperation: relatedness,
reciprocity, partner choice, and punishment. A systematic search of the
microfinance literature yielded 73 effect estimates for 11 proxies of
evolutionary mechanisms analysed in 11 separate meta-analyses.
Punishment-based variables showed the strongest positive meta-analytic
associations with loan repayment, with mixed results for other mechanisms.
However, estimates varied widely in their certainty, with generally high
levels of between-study heterogeneity. Our results provide some evidence for
evolutionary mechanisms supporting cooperation in real-world contexts, but
also indicate there are non-generalisable findings and/or reproducibility
issues in the microfinance literature. |