Sunday, November 1, 2009

Will humans ever stop fighting wars

This week's Radio Lab has a fascinating program on the, somewhat broad, topic of change. Go listen to the podcast; it's much more entertaining than my thoughts below.

They start with the question: will humans ever stop fighting wars?

They cite a contemporary survey claiming 90% of Americans say "no". In the 1980s this percentage was lower and people were optimistic for a peaceful future. I'm sure people's optimism for peace correlates with their awareness of war at the time. With the US being at war since 2002 it's no wonder that a peaceful future is hard to imagine.

A natural cognitive bias makes us over-estimate change that will happen in the short term and under-estimate long term change.

Short term we will probably have constant war. There has been a war somewhere in the world everyday since WW2.

Long-long term, a number of factors could change. Space exploration could lead to us mining the asteroid belt and effectively unlimited resources. Virtual reality could let each of us live in our own perfect world. We are evolving and we could in the long term become a more peaceful species. Radio Lab touches on this last point

The show's first story looks at how quickly a cultural change can affect aggression in society. The example is a great one: a troop of baboons in Kenya.  A disease wipes out the alpha males in the troop. Without the more aggressive members, the troop becomes peaceful. Males would reciprocate female grooming and, very unusually, even male-male grooming became common. 20 years later the troop remains peaceful. New-comers to the group would learn non aggressive interaction. It's a small natural experiment that seems to support the old adage "If the world were run by women, there would be no wars."

It's clear that aggression will be culturally influenced, no doubt even more strongly in humans. Whether your "tribe" is a biker gang or a group of artists will affect your view on how to resolve conflict.

An evolutionary biologist is interviewed and sceptical of the result: until there is a genetic change baboons are still baboons and, presumably he means, naturally aggressive. But this "natural" state will depend on circumstance. It seems clear to me that baboons have a spectrum of aggressive behaviour and in the right circumstances can really be quite peaceful.


Radio Lab's 3rd part comes back to evolutionary biology and looks at a Russian experiment in domestication. A group of foxes was bred selectively to remove the foxes that were scared if humans. It's fascinating that the domestication process that took thousands to years to turn wolves into dogs can, when finally tuned and concentrated, turn foxes into pets in 10 years. The more interesting number I would want to hear, is how many generations this took.

This makes me think of selective breeding in the context of reversion to the mean. The original biological experiment on this was looking at bean sizes. These have a normal distribution. Over generations, larger beans will have descendants that are smaller, or rather, closer to the mean. For humans, two genius parents will typically expect their child to be less brilliant than themselves.

The implication of the domestication story is that selective breeding can alter the mean. I then wonder how permanent a change this is. If a domesticated population is then allowed to breed naturally, will they revert to their previous mean? I guess it would depend on the natural evolutionary pressures they find themselves under, once the absence of the artificial evolutionary pressure of domestication. In most circumstances, fear of humans is a pretty sensible default behaviour for animals.

Back to our friendly foxes, we find that not only do they become friendly, but they experience physical changes. Their ears become floppier, their tails more curly, their teeth smaller, their coats multicoloured, their bones thinner and thus their faces more feminine. Essentially they became more dog-like. Why does this happen? Radio Lab says: "No one knows why"

This is the point in the program where I jump up in my seat with my hand raised, "Me! Me! I know the answer to this one! Hormone levels are influenced in part by genetics. Domestication selects for those animals that are less aggressive. These animals have less testosterone and more oestrogen. Hormones also affect physical appearance, thus the foxes become more feminine."

Radio Labs' evolutionary biologist has a different theory: he also relates the changes to brain chemistry, but picks on adrenaline and the neural crescent cells that build the adrenaline glands. The implication is that selecting away from aggression selects away from adrenalin and the crescent cells that also build pointy ears and sharp teeth. Oh well, guess I've still got plenty to learn about evolutionary biology.

Radio Lab notes that humans are also physically changing. Our teeth have become smaller and other domesticated attributes. The theory goes, that as human tribes have grown in size, cooperative behaviours have become increasingly important. Overly aggressive individuals have been selected out of the gene pool.

I've got to wonder how much aggression we can eliminate. Corporate culture seems to attract and encourage aggressive behaviour. In contrast to the idea that society will select for empathy, sociopaths seem to be successful in companies. This success carries over into financial success and elevated status in society. High status correlates with having more children than average. So are we really breeding aggression out of species or will we just create more sociopaths?