Reciprocal cooperation between unrelated rats depends on cost to donor and benefit to recipient

Contingent cooperation between wild female baboons

(2010) D. L. Cheney et al.   PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

Towards a bottom-up perspective on animal and human cognition

(2010) Frans B.M. de Waal et al.   TRENDS IN COGNITIVE SCIENCES

The relative roles of kinship and reciprocity in explaining primate altruism

(2009) Gabriele Schino et al.   ECOLOGY LETTERS

ASSORTMENT AND THE EVOLUTION OF GENERALIZED RECIPROCITY

(2009) Daniel J. Rankin et al.   EVOLUTION

GREENBEARDS

(2009) Andy Gardner et al.   EVOLUTION

Cooperation between non-kin in animal societies

(2009) Tim Clutton-Brock   NATURE

Giving is self-rewarding for monkeys

(2008) F. B. M. de Waal et al.   PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

Putting the Altruism Back into Altruism: The Evolution of Empathy

(2007) Frans B.M. de Waal   Annual Review of Psychology