Page "Altruism" Paragraph 25

:: People are more likely to cooperate on a task if they can communicate with one another first.

This may be due to better assessments of cooperativeness or due to exchange of promises.

They are more cooperative if they can gradually build trust, instead of being asked to give extensive help immediately.

Direct reciprocity and cooperation in a group can be increased by changing the focus and incentives from intra-group competition to larger scale competitions such as between groups or against the general population.

Thus, giving grades and promotions based only on an individual's performance relative to a small local group, as is common, may reduce cooperative behaviors in the group.