Re: [xmca] Born Open Minded

[Martin Packer <packer@duq.edu>]

I've been mulling over just how risky and expensive it is for evolution to produce a human baby. Evidently it is significantly easier to build the genome for a creature that responds instinctively to its surroundings from the very start, such as a lizard. I have no idea how behavior is programed in the genes, but obviously it can be done, however in the case of the human newborn the strategy has been to program very little, not much more than the basics of respiration and digestion, and to assume that other people, caregivers, will pick up the slack.

The benefits are clear. The great thing about a computer is that it is a Universal Machine, one that can be programed to perform a vast variety of tasks. Or at least it is a universal *information* machine, programable to carry out any task that requires manipulation of information. When I was a teenager I was actually rooting for analog computers: these are collections of operational amplifiers that solve differential equations not numerically, following the rules of computation as a digital computer does, but by analogy, using resistors and capacitors to make electrons flow the way the variables do. Very elegant. The big down-side to analog computers, however, is that they are like lizards; they solve one equation very well, but they have to be broken down and rebuilt to solve a different one. 

A computer is not so universal that it can wash dishes or fix the plumbing. But the human baby is such a universal machine that it can even do these when it grows up. So the benefits of flexibility and universal programmability are obvious. But the risks of evolving a neonate that can do nothing important for itself are surely staggering. 

One of my responsibilities as a neonatal researcher was to be on call for the moment of birth, at which point I would step into the operating room with a white coat and a clipboard. Of the more than a hundred births I attended a few stand out all these years later. One was when the doctor cut the umbilical cord instead of clamping it, and we were all covered in blood but no harm was done. But another was when the mother refused to look at her baby once it was born. The child was handed to her but she turned her head away in something between denial and disgust. It was shocking, in part because it was such unusual behavior. But the deeper shock, looking back at it, was the concern it was impossible not to have about the child's future.

A helpless newborn is only a good evolutionary investment if other people are willing and able to do for it what it cannot do for itself. The neonate has to be able to involve these others, communicate its needs to them and motivate them to provide satisfaction. This is risky because if something goes wrong the newborn has no other survival strategy to fall back on. It can't burrow down and encyst itself until better times arrive. But it is also expensive, because a whole infrastructure has to be in place for the investment to pay off. Evolution has to build family and community and culture first, before it makes any sense to build a helpless baby. Of course in practice the two edge along hand in hand. But still the fact that it is human nature to rely on nurture seems a precarious strategy, a little like trading derivatives. 

The payoff must make it worth while. And the payoff cannot simply be cultural diversity; I don't believe that evolution is a liberal. 

Neanderthals apparently lived without changing their habits for hundreds of thousands of years. They hunted meat over long distances, using a simple, traditional toolkit. The lifestyle obviously worked - they survived far longer than homo sapiens has to date. But we took them out. Their success trapped them: hunting game works well for a small group that is continuously moving over a large territory. But it is larger groups that achieve cultural innovation, so the Neanderthals were in a situation where they *couldn't* change. Their population density could never get high enough for new tools, material and psychological, to develop. 

Homo sapiens, in contrast, was able to form the groups that deliver the goods. Cultural innovation requires both 'enculturability' and flexibility on the part of its newcomers, but in return it provides them the resources to enter a vast variety of environments and exploit and transform them. This must have been the payoff: where lizards are born exquisitely programmed in how to act in their environment, humans are born helpless and so become able to adapt their environment as they wish.

Martin

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