Table 6.

Pearson’s correlation coefficients between rounds and overall cooperation in the three conditions. Cooperation varies only in the zero density condition.

	round 26–50	round 34–50	round 38–50
condition zero	−3.50**	−0.25	−1.92#
condition low	−1.53	−0.61	−0.87
condition high	1.71	−0.43	1.20

Significance level: ***<0.001, **<0.01, *<0.05, ^#<0.1.