In contrast to other examples of ultrasociality19–22 (for example, clones, bee hives or termite colonies), human cooperation is due less to kin selection than to cultural forces rooted in pervasive moral systems. From hunter tribes and village communities to nation states and global enterprises, the economic effects of nepotism, although certainly present, are minor compared with those of reciprocity.

Nowak, M. A., & Sigmund, K, Evolution of Indirect Recip…, loc. 6