Chapter 8 Summary and Analysis

The author now investigates if a parent should show favoritism to one offspring; for instance, protect or feed one child more than others. R.L. Trivers invents a way to think about parental care called "Parental Investment", or PI. Higher PI means giving more to one at the expense of another child. Dawkins wants to expand the idea to all adult care givers, including related adults. He calls this AI or Altruistic Investment. There's only so much AI energy, time, and effort any creature can offer.

Genetically, there is no reason to favor one child. Each is related to the parent by one half. But if there is something wrong with one of the offspring, it will take more energy to raise and will "cheat" the others. Some pigs do eat the runt of the litter and use him to make...