Documents Be kind or be left behind. 1.Helping in times of danger 2.Sharing food 3.Helping the ill,

Slide 1 Be kind or be left behind Slide 2 http://www.cdnresearch.net/pubs/others/trivers_1971_recip.pdf 1.Helping in times of danger 2.Sharing food 3.Helping the ill, the…