Steven Pinker -- How the Mind Works - Hampshire High Italian ...

400 | HOW THE MIND WORKSone-in-eight chance that a copy is lying inside a first cousin, and so on. Agene that built a brain that made its owner help its relatives would indirectlyhelp to replicate itself. The biologist William Hamilton noted thatif the benefit to the relative, multiplied by the probability that a gene isshared, exceeds the cost to the animal, that gene would spread in thepopulation. Hamilton developed and formalized an idea that had beenentertained by several other biologists as well, most famously in a wisecrackby the biologist J. B. S. Haldane when he was asked if he wiould laydown his life for his brother. "No," he said, "but for two brothers or eightcousins."When an animal behaves to benefit another animal at a cost to itself,biologists call it altruism. When altruism evolves because the altruist isrelated to the beneficiary so the altruism-causing gene benefits itself,they call it kin selection. But when we look into the psychology of theanimal doing the behaving, we can give the phenomenon another name:love.The essence of love is feeling pleasure in another's well-being and painin its harm. These feelings motivate acts that benefit the loved one, likenurturing, feeding, and protecting. We now understand why many animals,including humans, love their children, parents, grandparents,grandchildren, siblings, aunts, uncles, nephews, nieces, and cousins: peoplehelping relatives equals genes helping themselves. The sacrificesmade for love are modulated by the degree of relatedness: people makemore sacrifices for their children than for their nephews and nieces. Theyare modulated by the expected reproductive life of the beneficiary: parentssacrifice more for children, who have a longer life ahead of them,than children sacrifice for parents. And they are modulated by the beneficiary'sown feelings of love. People love their grandmothers not becausetheir grandmothers are expected to reproduce, but because their grandmotherslove them, and love the rest of their family. That is, you help peoplewho enjoy helping you and helping your relatives. That is also whymen and women fall in love. The other parent of my child has as much ofa genetic stake in the child as I do, so what is good for her is good for me.Many people think that the theory of the selfish gene says that "animalstry to spread their genes." That misstates the facts and it misstatesthe theory. Animals, including most people, know nothing about geneticsand care even less. People love their children not because they want tospread their genes (consciously or unconsciously) but because they can'thelp it. That love makes them try to keep their children warm, fed, and