It’s a sports riot, and a Caucasian man is deciding who to hit between two already fighting men. One man is African American and wearing a Michigan State hat, the other is Caucasian and wearing a Wolverines hat. What bit of information do we need to predict who he’ll hit?
What color is our hero’s hat?
This may seem obvious, but it’s utterly beyond the sort of gene-centric kin selection-based explanations for why humans cooperate that you read or hear or watch about. At issue is whether people will cooperate with people who are likely to share their genes or people who are part of some group with which they identify. I’m not saying that kin selection was a non-force in shaping human behavior, just that it doesn’t explain why the white guy in the green hat hit the white guy in the blue hat and high-fived the black guy in the green hat. Neither, I think, does it explain things like genocide or racism, as some fear. Twice recently[1], I’ve seen the celebrated Price Equation for evolution by group selection be explained as though it is the same of Hamilton’s rule for evolution by (strictly genetic) inclusive fitness. The latter goes like this: “I’d sacrifice my life for three brothers, because they would have between them 3 x 0.5 = 1.5 copies of the genes I’m currently carrying, which is more than 1.0, so my genes would benefit from the action even though I’d die, so there you have it.” Price’s idea would go more like this: “When my tribe is competing against other tribes, and the others within my tribe tend to behave like me, we’re all in it together and it makes sense to cooperate.” If people want to talk about Price (and there's a lot to talk about), they could at least make an effort to give him credit for his contribution [2]. I know there's a tendency to simplify concepts when addressing a general audience, but a line is crossed when you actually substitute a simpler (and completely separate) idea for a more complicated one.
The role of group-selected behaviors in shaping human cooperation has a basic importance that extends far beyond the modern bloodbath [3][4] currently unfolding in academia over group vs. kin selection, it’s about how people view things like genocide and how willing we are to accept them as an inevitable part of human nature. (See this documentary, by Adam Curtis and the BBC, who makes this crucial mistake and arrives at terrifying conclusions before calling on us to, I guess, fight to control our overwhelming natural racism?) If you just hear the first, kin-based explanation above, you start thinking about whom you’d help and whom you wouldn’t. Well I’d help a cousin for sure, I’d even help out a second nephew, if he wasn’t asking too much. Why, I suppose I’d even help out other folks of Irish/Scotch ancestry, because we’d probably share some genes. But whom would I not help out? I suppose only the people I knew were least likely to share genes with me…maybe people whose ancestors came from very different parts of the world than me, for example. And if I could help a person more like me by hurting someone less like me…
You get the idea. Starting from this highly restricted view of social evolution theory, it’s not at all surprising that the aforementioned documentary concluded that intrinsic human nature is a dark, evil thing. Almost universally appealing concepts like selflessly helping out strangers go by the wayside, to be explained away as a result of botched target selection[5], like a dog trying to hump a rooster.
Thank god it doesn’t work like that, and the guy in the green hat would 9 times out of 10 hit the guy in the blue hat. People will probably always want to hit someone, to some degree, but the large-scale slaughters that warrant the term “genocide” are less about some evil, immutable biological tendency to attack genetically different people than the less sensational and more fickle (but very real) forces of economics and history. And that people want to have a group (team, tribe, etc.) and compete against other groups is not a new insight, but this is a far cry from the claim that humans will naturally try to kill those physically unlike them. The desire for group-level competitions can be relatively constructively channeled into a highly ceremonialized mode of warfare, designed (usually) to minimize the actual violence occurring: sports. For example, epic lacrosse games at least partially replaced warfare in ending disputes between some more or less friendly Native American tribes.
The point is that this group selection framework far more accurately predicts everyday human behavior, and the good news is that we can work with within- and between-group forces. If human sociality really was the result of kin selection based solely on genetic similarity, well then I think we'd be living in a much nastier society. Would we even have ideals like equality and diversity at all? Something to mull over while we're all cheering on Michigan State!
[1] Episode 3 of Adam Curtis' BBC documentary series All Watched Over by Machines of Loving Grace.
http://www.radiolab.org/2010/dec/14/
[2] For fans of modern kin selection theory, yes, modern versions of Hamilton’s rule that focus on phenotypes (not genotypes) can be brought into compliance with the very general Price Equation. But equating Price’s equation with the 1964 view of strictly genetic kin selection is not only historically and mathematically inaccurate, it misleads in a major way when we start thinking about issues of cooperation and spite in humans.
[3] Nowak, M. A, C. E Tarnita, and E. O Wilson. 2010. “The evolution of eusociality.” Nature 466 (7310): 1057–1062.
[4] Abbot, P., J. Abe, J. Alcock, S. Alizon, J. A.C Alpedrinha, M. Andersson, J. B Andre, et al. 2011. “Inclusive fitness theory and eusociality.” Nature 471 (7339): E1–E4.
[5] Henrich, Joseph. 2004. “Cultural group selection, coevolutionary processes and large-scale cooperation.” Journal of Economic Behavior & Organization 53 (1) (January): 3-35. doi:16/S0167-2681(03)00094-5.
