Cooperation confounds us: Humans are the only members of the animal kingdom to display this tendency to the extent that we do, and it’s an expensive endeavor with no guarantee of reciprocal rewards. While we continue to look for answers about how and why cooperation may have emerged in human social and cultural evolution, we are beginning to trace the developmental roots of prosocial behaviors. A recent PLoS paper presents evidence that children as young as 15 months old may have a rudimentary sense of fairness
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Cooperation Is Child’s Play