A recent exchange on evolution and human nature between myself, Paul Armstrong, and others on Boston.Com boards ...

http://boards.boston.com/n/pfx/forum.aspx?msg=281.27&nav=messages&webtag=bc-news

TS editing note: I've intentionally eliminated some unhelpful responses from people. I also eliminated John Landon's ("nemonemini" -- http://eonix.8m.com/) responses although they have some value. I did this because they are a distraction more than a help to the threads I am most interested in. He sometimes makes good points, but he is so combative that constructive dialog with him is almost impossible. I think he essentially makes two points: (1) he supports a periodic ("Eonic") theory of cultural evolution which is entirely non-Darwinian, and (2) he argues that Darwinian mechanisms "cannot explain human evolution." This second point is problematic because of his systematic refusal to either distinguish biological from cultural evolution or to acknowledge even in principle what natural selection can potentially explain.
Treating his ideas fairly would require a whole separate discussion (and a more reasonable advocate to represent them!).

Here are the selected posts ...

News board
Folder: Ideas
Discussion: Understanding human nature

1 Mar-26 From: BostonDotCom To: ALL
In ''The evolutionary revolutionary,'' Drake Bennett profiles Robert Trivers, who wrote a series of papers in the 1970s that provided the intellectual basis for evolutionary psychology, a discipline which holds that human behaviors from rape to religion are inborn products of evolution. Does natural selection provide the key to understanding human nature? Or do such explanations neglect the importance of culture?


4 Mar-28 From: sabine To: BostonDotCom
Trivers, Pinker and their followers grossly undestimate the power of culture in their explanations of human behavior. Dawkins seems to be allowiing culture back into the picture in his most recent contribution. All three, however, rely heavily on anecdotal data when dealing with homo sapiens (as versus quantifiable evidence in other realms). Bio-reductionism has, I suppose, gained favor due to its association with "real" science and the abject failure of the social sciences to generate a satisfactory pardigm. S.J. Gould's untimely death silenced the most promising voice on these matters. He understood cultural evolution as well or more insightfully than the bulk of current anthropologists, and certainly better than his selectionist peer group.

5 Mar-28 From: jsb To: BostonDotCom
Some thoughts on the Robert Trivers article:

1 What a fascinating guy!

2 The objections I’ve had, as an amateur, to socio-biology, aren’t so much to the subject itself, but to the stupid popularizations, where it quickly becomes just a version of the “Playboy Philosophy”. As if it took Stephen Pinker to discover that tendencies towards adultery are part of human nature. I think Hank Williams discovered that a while ago, without going to Harvard....
An interesting project would be to try to tease out the evolutionary meaning of the very human project of trying to resist the all too human temptations to lie, cheat and steal, etc. In other words, where did this morality come from, that we can’t get away from? Hugh Heffner can just blame it on the Puritans, and say to hell with it, but that’s not really good enough. Puritans, and all other moralists, are products of evolution, too, in some sense, aren't we?

3 The self-deception project: great topic! Sartre wrote some brilliant stuff about it. Trivers’ early version, as presented in the article, isn’t very convincing. He says self-delusion helps you lie more effectively, but:

a. Liars in general aren’t notably self-deluded. The seducer doesn’t believe that he (or she) isn’t already married, and the con-artist doesn’t believe he or she is going to make you rich. The corrupt politician doesn’t believe anything at all. And yet they all lie and deceive pretty successfully.

b. Many self-delusions aren’t about things you lie about to other people. A classic case is when someone like me starts thinking “Hey, the grey hair looks rakish, and from some angles, you wouldn’t even notice the extra thirty (or forty) lbs: basically, I’m still the attractive guy I was twenty (or thirty) years ago. Only smarter.” This common kind of delusion isn’t something you can fool anybody else about, only yourself.

c. So, Trivers is (in the Ideas article, at least) only looking at a small corner of the large realm of self-deception, and a small corner of the large realm of deceiving others, and suggesting there may be interesting overlap in there. Well, maybe so. But there are still the large categories of cynical deceivers, and poor slobs who fool only themselves. So, there are a few more chapters to write in the book of deception. I’m looking forward to reading it.

17 Apr-4 From: toddstark To: BostonDotCom
Asking whether natural selection is "sufficient" or "the answer" to explaining human nature seems to involve a misunderstanding of the concept itself. Selection is a model for explaining the spread of variation. It seems to me that it should be logically obvious that explaining the spread of variation cannot by itself be a complete explanation of the nature of anything. However by the same token, failing to explain how some variation spreads through a population and other variation does not would make us blind to a big part of the picture.

Selection is most probably neccessary and almost certainly not sufficient for the most interesting explanatory tasks relevant to human nature. I think natural selection is an important and perhaps essential tool of analysis for both the genetically inherited aspects of our species, and the elements of culture that we transmit by other means.

Culture evolves just as genomes do, although by different mechanisms. Yet selection still plays a role. Inherited learning mechanisms of a variety of kinds play an important role in individual differences; while economics, cultural heritage, and selection all probably play more important roles in group differences. Sure, there is potentially much merit to periodic and linear theories of history as well, but they aren't neccessarily mutually exclusive with the explanatory power of selection theory and population mathematics.

Two recent thought-provoking books relevant to explaining human behavior in broad terms relevant to cultural or biological evolution ...

Richard Nisbett --> "The Geography of Thought" -- reviews experimental evidence that Nisbett believes shows how the way we live affects what we focus on, which affects the way we think and perceive things in a globally pervasive manner. Shows how the influence of geography, ecology, economics, and social structure influences cognitive processes in important ways not limited to the controversial effects of different languages on cognition. Culture and ecology do matter, and affect our thinking in a fundamental way that a universal model of human cognitive modules might not do justice to.

Boyd and Richerson --> "Not By Genes Alone" -- their model of gene-culture coevolution, showing why culture matters and how it is affected by selection in a different manner than the genome. Also how genes and culture influence each other in both directions. Roughly speaking, a more scientific and less narrow version of the "meme" idea. Again, culture does matter, but not in a way that makes human beings a blank slate.

kind regards,

Todd Stark


18 Apr-5 From: kristier To: BostonDotCom
Natural selection states that only those who are best adapted to their environment will survive and those who have less adapted are more likely to be eliminated. Humans naturally select groups based on characteristics that are similar. This group association is something that is in our nature, just like how we gravitate towards forming our own family groups and social networks. Humans form their own groups and tend to exclude others from their groups and sometimes develop preconcieved notions about these other groups. Group selection can be a good or bad thing, but it all depends on how ones groups treats others outside ones group. Groups that form preconcieved notions about other groups may consider themselves superior or inferior to certain groups. One example would be groups of conflicting ethnicities that will sometimes claim that one group is superior over the other, also known as Social Darwinism. Social Darwinism, which the Nazi's used in WWII, caused groups who believe they are superior to wipe out other groups they consider inferior. Natural Selection can not be prevented. As long as we associate ourselves with others by forming groups, this hierarchy can't be stopped.

19 Apr-5 From: Dr._Paul_Armstrong To: toddstark
Thank you Todd for your input.

If I may make a couple of comments.

I agree that there are other means of evolution, like drift. However, natural selection is a sufficient process by which evolutin can occur, i.e. sufficient, but not necessary. On the other hand, for adaptation and/or speciation, then natural selection is both necessary and sufficient.

Regarding, the origin of variation; it IS NOT natural selection. Natural selection decreases variation. Consider 2 alleles at a locus in a population. One allele is slightly advantageous over the other. Selection will eventually eliminate the less advantageous allele, i.e. decrease variation.

Culture DOES NOT evolve as genomes do. Cultural evolution evolves in a Lamarkian manner, i.e. the passing on of acquired characterisitics. This is precluded in biological evolution.

Finally, memes are in no way like genes (I know you did not claim this, but that is what the memeists contend). In fact, that are not real entities, and therefore are not amenable to scientific experimentation.

Thank you for the references, another is Dennet, Darwin's Dangerous Idea. However, I agree with Stepehn J. Gould's assessment, that cultural evolution is not evolution at all.

For more on the subject from Gould, see;

http://www.stephenjaygould.org/


22 Apr-10 From: peterkirk To: BostonDotCom
To explain religious preferences or acts of crime according to Bennett is to attribute such actions to Natural Selection. By doing so, Bennett's theory undermines and denies human free will. Embracing religion has certainly not been proven to lead to a genetic advantage. Likewise, one does not see single men raping woman out of a "natural selective" need to propagate. While there can be no dismissing the argument that genetic traits survive and are passed from one generation to the next, people still posses a mind, a conscience, and a soul. These factors allow humans to make decisions regarding a rejection of religion or commiting a crime like rape. To act out of reason, and not passion or instinct, is what separates humans from other animals. We are all born with a soul, and we all have a choice.

23 Apr-11 From: toddstark To: Dr._Paul_Armstrong
Paul,

Thank you very much for your comments.

Paul: I agree that there are other means of evolution, like drift. However, natural selection is a sufficient process by which evolutin can occur, i.e. sufficient, but not necessary. On the other hand, for adaptation and/or speciation, then natural selection is both necessary and sufficient.

Todd: I'm a little confused by this. By my understanding, natural selection is not a theory of speciation. This would seem to me to trivialize a lot of important work that has been done to model the reproductive isolation of populations, and a lot of work still to be done.


Paul: Regarding, the origin of variation; it IS NOT natural selection. Natural selection decreases variation. Consider 2 alleles at a locus in a population. One allele is slightly advantageous over the other. Selection will eventually eliminate the less advantageous allele, i.e. decrease variation.


Todd: Again, I agree insofar as natural selection is not a model of the origin of variation, it is a model for the spread of variation.


Paul: Culture DOES NOT evolve as genomes do. Cultural evolution evolves in a Lamarkian manner, i.e. the passing on of acquired characterisitics. This is precluded in biological evolution.


Todd: Certainly, but neither of these statements precludes the Darwinian evolution of culture. The Darwinian mechanism doesn't require a genome nor does it require Mendelian inheritance. Neither is Darwinian evolution precluded by Lamarckian inheritance. For extended discussions, see Boyd and Richerson (Not By Genes Alone), also Peter Corning (Nature's Magic), and Steve Gould's doorstop has much of value to say about the root of the Darwinian evolution vs. its branches. In addition, David Hull has a wonderful example of Darwinian processes in the cultural activity of science in "Science as a Process."

The root is simply that (1) variation arises in a population, (2) that the variation affects its own reproduction, and (3) that the total number of variants is limited in some way.


Paul: Finally, memes are in no way like genes (I know you did not claim this, but that is what the memeists contend). In fact, that are not real entities, and therefore are not amenable to scientific experimentation.

Todd: My opinion is that this isn't entirely true, that there are some cultural variants that are somewhat like genes, however the more important point I want to make is that population models make no assumption that variants must be strictly particulate. I also don't think that cultural variants are themselves replicators in the sense that genes are often considered to be, but this doesn't neccessarily break the natural selection model either.

What matters most, I hope you'll agree, is not whether other mechanisms happen to come into play, but the empirical question of whether selection affects the spread of cultural variants more than the "Lamarkian" guidance does. If so, then we are justified in using natural selection to model the spread of cultural variation, even though it is not the only mechanism in play. Why? ...

One main reason that I find it plausible that natural selection remains a viable factor in cultural evolution is that our cumulative achievements are so much greater than anything that anyone manages to achieve in a single generation. Henry Petroski has a series of books about engineering that point out how much cultural evolution is involved in something as simple as a paper clip or a pencil. We easily lose track of how much cultural variation has accumulated prior to the invention of something useful. The time frame over which useful cultural innovation actually happens is what makes it plausible to me that selection has an important effect.

As to whether cultural evolution is Darwinian, I admit that the jury is still out, but I insist that the idea should not be rejected out of hand just because simplistic versions of the idea have been abused or because cultural variants are very different from genes. The potential of applying population models to cultural innovation is great and the idea potentially quite testable.

kind regards,

Todd


24 Apr-11 From: toddstark To: peterkirk
I don't put much trust in sociobiological models that ignore the seemingly obvious fact that we often systematically do things that violate our own reproductive fitness. If genetic fitness were a good predictor of human behavior, we would be using it in a positive way as our behavioral science, rather than spending most of our time trying to explain the cases where it doesn't apply, like nationalism, moralistic punishment, suicide cults, and other phenomena that defy direct explanations based on the adaptation of small bands of hunter-gatherers to the Pleistocene environment. Trivers' reciprocal altruism concept works beautifully for small band reciprocal behavior, but fails completely for large group behavior where we cannot possibly track or manage the neccessary relationships for reciprocation.

That said, I don't agree with the "free will" argument either.

Mechanical models don't negate free will because they have nothing to do with free will, they are from a completely different tradition of reasoning. One is causal explanation, the other is folk psychology. It isn't adequate to say that because a mechanical model violates the intuitions of folk psychology that this proves that the mechanical model must be wrong. Of course formal causal models violate our folk psychological intuitions, that's exactly why they work so well (when they do). They allow us to predict things that our intuitions fail at. They provide us with deductive validity for our theories.

The folk psychological notion of free will is essentially an uncaused cause, whereas the scientific notion of cognitive choice is something closer a complex loop of causation. For example, so long as there is some way in which the frames and goals of reasoning can be influenced by information, there is no reason why "free will" cannot be represented in principle by information processing models. To say that mechanical explanations of human behavior are wrong simply because they don't allow for uncaused causes is circular reasoning in my opinion. The rejection of uncaused causes is quite deliberate and tremendously useful in science.

There is nothing about Darwinian explanation that requires all human behavior to directly serve the interests of our genes. Much of our behavior is demonstrably maladaptive from the perspective of reproductive fitness.

The tradeoffs involved in learning and performance probably prevent a powerful general purpose learning mechanism from evolving, or from being particularly useful to us even if it does evolve. However this doesn't prevent us from evolving information processing mechanisms and biases that serve what we now think of as our "free will."

The idea that we choose "freely" is rather more illusion than reality as it turns out. People rarely adopt a religion or political or social attitude that isn't predictable from their history and circumstances. Of course it makes sense to them, so they don't neccessarily view it as being coerced into that choice, and they say it is "freely made." Saying that people "freely" chose what we expect them to choose seems to me to beg the question of what "choosing freely" means. It appears that there is no substantive difference between the idea that our choices are the result of a complex deterministic causal model and the idea that they our choices are the result of "reasoning freely" from predictable conditions.

For the most part, it seems to me that criminal behavior can be explained in terms of impulsiveness of various kinds, leading us to violate the norms that normally constrain us by means of legal coercion, moral emotions, and moralistic punishment.

kind regards,

Todd

To explain religious preferences or acts of crime according to Bennett is to attribute such actions to Natural Selection. By doing so, Bennett's theory undermines and denies human free will. Embracing religion has certainly not been proven to lead to a genetic advantage. Likewise, one does not see single men raping woman out of a "natural selective" need to propagate. While there can be no dismissing the argument that genetic traits survive and are passed from one generation to the next, people still posses a mind, a conscience, and a soul. These factors allow humans to make decisions regarding a rejection of religion or commiting a crime like rape. To act out of reason, and not passion or instinct, is what separates humans from other animals. We are all born with a soul, and we all have a choice

25 Apr-12 From: Dr._Paul_Armstrong To: peterkirk
I presume you mean Dennett ("Darwin's Dangerous Idea") and not Bennett (Wayne Bennett from Rockland High School).

Many evolutionary biologists would agree with you. We are uncomfortable with the idea of an adaptive explanation for behavioral and cultural characteristics. We are not sure that they are testable, and therefore are not sure they are science.

An example of a good book that ends up being misleading to the educated lay person is Diamond's "The Third Chimp" where he induces these adaptive explanations for all sorts of human behavior, and I just cannot agrre with some of what he purports.

Regarding rape: if rape was a successful reproductive strategy, i.e. it would increase the fitness of the raper, then we would see more of it. For some number of reasons, it is not.

I don't agree with your last statements. How would one know that they're not acting insinctively. There's just no way to test that, nor the following statements about humans possessing a soul.

I'm a scientist, and evolutionary biology is a science, so I suggest we leave theology out of it.


26 Apr-12 From: Dr._Paul_Armstrong To: toddstark
Todd: I'm a little confused by this. By my understanding, natural selection is not a theory of speciation. This would seem to me to trivialize a lot of important work that has been done to model the reproductive isolation of populations, and a lot of work still to be done.

Paul: Natural selection is the process discovered by Darwin (and coincidentally, Wallace) by which the origin of species arise. So, in a Darwinian sense, it's not a theory of speciation, but the process by which speciation occurs. I.e., the source of biodiversity.

Todd: Again, I agree insofar as natural selection is not a model of the origin of variation, it is a model for the spread of variation.

Paul: If you're talking about the "spread" of biodiversity, then I now understand what you mean.

Todd: Certainly, but neither of these statements precludes the Darwinian evolution of culture. The Darwinian mechanism doesn't require a genome nor does it require Mendelian inheritance. Neither is Darwinian evolution precluded by Lamarckian inheritance. For extended discussions, see Boyd and Richerson (Not By Genes Alone), also Peter Corning (Nature's Magic), and Steve Gould's doorstop has much of value to say about the root of the Darwinian evolution vs. its branches. In addition, David Hull has a wonderful example of Darwinian processes in the cultural activity of science in "Science as a Process."

The root is simply that (1) variation arises in a population, (2) that the variation affects its own reproduction, and (3) that the total number of variants is limited in some way.

Paul: I think that, yes, it does. Darwinian evolution by natural selection requires 1) variation at a trait, 2) that trait to be heritable, 3) that more individuals are born than the environment can support so that natural selection can occur at that trait. Culture does not fall into this explanation (much like Lamarkianism) so it cannot be explained by evolutionary theory. I.e., culture does not evolve.

Regarding memes, I won't get into that discussion, since their existence is invented and their evolution is precluded by my explanation above. They are merely an analogy of genes, and a poor analogy at that.

Selection, in and of itself, is nothing without variation and heritability. Consider a population of mice living in and around a dump contaminated with a toxic substance that leaves 10% od the mice with no right back leg. This is a developmental defect and is not heritable. These mice are at a selective disadvantage but this selection is meaningless without heritability. Just so with culture. Cultural traits can change, be lost, be picked up again and not affect the lineages that have them, because they are not heritable, they are learned. So, without affect the lineages, the GENETIC LINEAGES, then, evolutionarily, they are blind.

Todd: One main reason that I find it plausible that natural selection remains a viable factor in cultural evolution is that our cumulative achievements are so much greater than anything that anyone manages to achieve in a single generation.

Paul: There is no endgame, no progression, in evolution. Progressin is an artefact, because we HAD to start out knowing less than we know today. Organismically, we had to start out simpler, as single cells, or the precursors to single cells. Therefore it LOOKS like life progresses from simpler to more complex, but that's an artefact of life's origins, independent of evolution.

Todd: As to whether cultural evolution is Darwinian, I admit that the jury is still out, but I insist that the idea should not be rejected out of hand...

Paul: I won't, because there is behavior that is testable, heritable, predictable and Darwinian. However, I will insist on any credible theory of cultural evolution or the evolution of cultural traits show how these traits have a genetic component, else, it's sociology and NOT evolutionary biology.

Todd, Thanks for your comments.


27 Apr-12 From: Dr._Paul_Armstrong To: toddstark
If I may intercede with some comments:

Todd: Trivers' reciprocal altruism concept works beautifully for small band reciprocal behavior, but fails completely for large group behavior where we cannot possibly track or manage the neccessary relationships for reciprocation.

Paul: This is true in today's society. But, what if these traits did not evolve in today's society. Have you heard of the 'ghosts of evolution past?' Perhaps, when these altruistic traits evolved, humans lived in small isolated bands of closely related individuals, with little migration between groups. Then, one could envision the evolution of altruism explained by inclusive fitness. This trait could have been retained even though our culture has changed. Consider how fast our cultures have changed relative to evolutionary time scales. We probably have many traits evolved during a time which, or a culture that is very different evolutionarily than the one we live in today.

29 12:06 PM From: toddstark To: Dr._Paul_Armstrong
Paul: However, I will insist on any credible theory of cultural evolution or the evolution of cultural traits show how these traits have a genetic component, else, it's sociology and NOT evolutionary biology.

Todd responds ...

A light dawns. Ok, this finally helps me make sense of why we have been going back and forth arguing over things we seem to agree about in principle.

Yes, a Darwinian theory of cultural evolution would indeed be a Darwinian sociology, not evolutionary biology. (Nor would it be a form of "Social Darwinism," since that was not a scientific theory but a political ideology based on competition between individuals or groups rather than culture). It would have to be consistent with evolutionary biology, but I agree that it would be confusing to say it was the same field because it is not based on genes, nor neccessarily any other discrete particulate unit of inheritance, it is Darwinian only in the sense that it is based upon the core principles of natural selection and therefore likely that some different form of population mathematics could potentially be useful in helping to model its spread.

Thank you very much for the help clarifying these points.

kind regards,

Todd


30 12:20 PM From: toddstark To: Dr._Paul_Armstrong
Todd: Trivers' reciprocal altruism concept works beautifully for small band reciprocal behavior, but fails completely for large group behavior where we cannot possibly track or manage the neccessary relationships for reciprocation.

Paul: This is true in today's society. But, what if these traits did not evolve in today's society. Have you heard of the 'ghosts of evolution past?' Perhaps, when these altruistic traits evolved, humans lived in small isolated bands of closely related individuals, with little migration between groups. Then, one could envision the evolution of altruism explained by inclusive fitness. This trait could have been retained even though our culture has changed. Consider how fast our cultures have changed relative to evolutionary time scales. We probably have many traits evolved during a time which, or a culture that is very different evolutionarily than the one we live in today.

I think one main reason that many evolutionary theorists assume that Pleistocene humans lived in small bands is that it seems to make at least some sense of our social nature, as you suggest. However, I just don't see how living in small bands could explain nationalism, the psychology of religion, or much of human social psychology. I suspect that various fundamental aspects of human social behavior, such as role-taking, mass "strong" reciprocity, and the massive alignments of social and political movements are difficult or even impossible to explain in terms of adaptations to life in small bands. The hypothesis that Pleistocene humans may have lived in linked tribal organizations of thousands, (similar to the Plains Indians) is probably equally consistent with the available evidence as is the small band hypothesis.

If our social behavior is an adaptation to life in tribes of thousands rather than small bands, additional mechanisms become plausible to explain some of the things like nationalism that currently make little sense (to me) as some extension of a "ghost" of small band behavior. If people adapted to distinguish one small band from another, why should they suddenly see themselves as members of the same nation or religion as enormous numbers of others and act on that identity?

Ignoring the social reality isn't the right choice for evolutionary biology, explaining it is the right choice, and that probably requires some form of co-evolutoonary theory between genes and culture, where the undeniable role of culture in our social behavior can be better understood.

kind regards,

Todd