Interesting Topics on Evolution

What ethical hangups ?

Bringing back one Neanderthal? What are you going to do, make a pet out of the poor thing?

"a scientific education is, to a considerable extent, an exercise in taming the authority of one’s intuition."

The existence of consciousness seems to imply that the physical description of the universe, in spite of its richness and explanatory power, is only part of the truth,

[The existence of consciousness seems to imply that] the natural order is far less austere than it would be if physics and chemistry accounted for everything.

Oxitocin is old news.

needs to think less like the ol' time philosopher and more like a computer-literate, information theory-savvy systems analyst or engineer.

Steven Pinker's the man.

The Blank Slate The Modern-Denial of Human Nature

by Steven Pinker

Viking, New York, 2002. 527 pp. $27.95. ISBN 0-670-03151-8.

Is it really the case that, as Steven Pinker claims in The Blank Slate, the biological underpinning of human behavior is denied by most people? Almost daily we are told about genes for maternal behavior, promiscuity, homosexuality, language, and much else. Certainly, the simplistic idea of a straightforward pathway from gene to behavior has had its severe critics (quite properly, in my view): genes code for proteins, not behavior. However, the center of that academic debate is not about whether genes influence behavior but rather how they do so. Pinker is concerned with a very different debate between the natural and the social sciences. He argues that the social sciences are dominated by a belief that all of each individual's characteristics are generated by that person's experience. This looks like a caricature to me, one used to sustain yet another round of the tedious and increasingly irrelevant nature-nurture debate. It is all too easy to pour scorn on stupid arguments or on those people suffering from cultural lag, and Pinker should have resisted this temptation. He undoubtedly writes well and is able to express complex ideas in ways that make them intelligible to lay people. Yet too frequently he overstates his case.

Pinker bases his charge against the naive social scientist on three strands of current scientific inquiry: cognitive psychology, behavior genetics, and evolutionary psychology. The cognitive psychologists have uncovered rules that underlie and generate highly complex behavior. No quarrel with that. But to argue that the rules are, therefore, the basis of "real" human nature is to miss a crucial point. Chess has clear rules, which can be explained to a child. Yet, the interest and the richness of the game lie in what can be generated by those rules.

Behavioral genetics has established beyond all reasonable doubt that many individual differences in behavior can be attributed to genetic differences. However, the notion that the variability in behavior can be partitioned into genetic and environmental components is utterly misleading. Doing so ignores the rich and crucial interplay between the developing individual and his or her social and physical world. The estimates of heritability, with which Pinker seems completely comfortable, depend on the population of individuals and the range of environments sampled. Worse, the effects of a particular set of genes depend critically on the environment in which they are expressed, while the effects of a particular sort of environment depend on the individual's genes. Finally, heritability estimates say nothing about the ways in which genes and environment contribute to the biological and psychological processes of development. Walking on two legs is a fundamental property of being human, and it is one of the more obvious biological differences between humans and other great apes such as chimpanzees or gorillas. Although it depends heavily on genes, it has a heritability of zero because human variability in this respect depends on the vagaries of the environment. Pinker appears to miss the irony that the dependence of high heritibilities on human diversity conflicts with conclusions from the other modern subject he draws on for his attack on the social scientists--the evidence for human universals derived from the work by evolutionary psychologists.

Like many biologists, I regard proposals about the evolution and current utility of behavior as helpful in making sense of behavior. But it does not follow that all examples of present-day behaviors that clearly benefit the individual in the modern world are products of evolution. The combination of oral linguistic ability and manual dexterity, both of which are doubtless derived from past evolutionary pressures, generated written language in several parts of the world in the last 6000 years. IT is not at all likely that the different forms of written language are adaptive in the sense of having been shaped by Darwinian evolution. Moreover, proposals about past evolutionary pressures or current utility must leave open the question of how the behavior develops. Whether or not an individual's development involves some "instruction" from a normally stable feature of the environment, or whether it would be changed by altering the prevailing social and physical environment, cannot be deduced from even the most plausible evolutionary or functional argument.

Part of the problem is that Pinker is so vague in his use of the term instinct, on which much of his conception of human nature depends. Apart from its colloquial uses, the term instinct has at least nine scientific meanings: present at birth (or at a particular stage of development), not learned, developed before it can be used, unchanged once developed, shared by all members of the species (or at least of the same sex and age), organized into a distinct behavioral system (such as foraging), served by a distinct neural module, adapted during evolution, and differences among individuals that are due to their possession of different genes. One use does not necessarily imply another even though people often assume, without evidence, that it does. Behavior that has probably been shaped by Darwinian evolution and appears, ready-formed, without opportunities for learning may be changed in form and the circumstances of expression by subsequent experience. The human smile is a good example. This matters because what Pinker happily calls human nature is in reality individual nature and depends critically on the circumstances of that person's life.

Where do these shortcomings in the argument leave Pinker's thesis about human nature? In poor shape in my view. Saloon-bar assertions do not lead to the balanced discussion that should be generated on a topic as important as this one, and they do a disservice to the really powerful biological arguments that can be deployed. Furthermore, the misplaced combative style delays the honest synthesis Pinker professes he wants so much. I fear that The Blank Slate will become a happy hunting ground for the social scientists already predisposed to be skeptical about evolutionary thinking and that the wretched unnecessary debate over human nature is due for yet another silly round.

Not sure of your point here.

No doubt the fields relating to evolution theory and its implications for humanity have been full of controversy and debate going back decades and decades now.

Indeed, it's Steven Pinker's artful handling of the subjects, the controversies, and the particular PUSH FORWARD he reps for esp through the rolling hills of bullshit (btw, not unlike Dawkins') explains his following.

The whole shebang is steeped in history, and the latter in controversy. Curious how long you've been following along. My attention to Dawkins, Stevens, and evolutionary theory and its implications vis a vis culture goes back 30 years now. Even the recent history, something like a soap opera, is full of story.