@article{stevens_cushman_hauser_2005, 
  title={Evolving the Psychological Mechanisms for Cooperation}, 
  volume={36}, 
  DOI={10.1146/annurev.ecolsys.36.113004.083814}, 
  publisher={Annual Reviews}, 
  author={Stevens and Cushman and Hauser}, 
  year={2005}
  }