The Selfish Gene

by Richard Dawkins

According to this theory then, senile decay is simply a by-product of the accumulation in the gene pool of late-acting lethal and semi-lethal genes, which have been allowed to slip through the net of natural selection simply because they are late-acting.

Dying of old age illness has evolutionary sense

Grandparents and grandchildren have, genetically speaking, equal reason to behave altruistically to each other, since they share of each other’s genes. But if the grandchildren have the greater expectation of life, genes for grandparent to grandchild altruism have a higher selective advantage than genes for grandchild to grandparent altruism. It is quite possible for the net benefit of assisting a young distant relative to exceed the net benefit of assisting an old close relative.

Have you ever heard a litter of piglets squealing to be first on the scene when the mother sow lies down to feed them? Or little boys fighting over the last slice of cake? Selfish greed seems to characterize much of child behaviour.

especially in humans, children seem to not have much sense of generosity towards others

delayed reciprocal altruism can evolve in species that are capable of recognizing and remembering each other as individuals.

Reciprocity works only when you can remember who helped