Saturday, March 12, 2011

Social brains

Here is a foundational question that is worth asking periodically in the philosophy of social science: what is the relationship between the evolutionary history of the human species and our current social and cultural behavior? The sociobiologists had one answer to the question: many of our current social behaviors are an expression, through the medium of the evolved central nervous system, of the compounding of a set of social instincts that were favored by natural selection. E. O. Wilson describes the intellectual agenda of sociobiology in these terms in In Search of Nature:
Much of the new effort falls within a discipline called sociobiology, which is defined as the systematic study of the biological basis of social behavior in every kind of organism, including man, and is being pieced together with contributions from biology, psychology, and anthropology. There is nothing new about analyzing social behavior, and even the word "sociobiology" has been around for years. What is new is the way facts and ideas are being extracted from their traditional matrix of psychology and ethology (the natural history of animal behavior) and reassembled in compliance with the principles of genetics and ecology. ...  With genetic evolution always in mind, sociobiologists search for the ways in which the myriad forms of social organization adapt particular species to the special opportunities and dangers encountered in their environment. (76)
This view sometimes takes the form of a very direct connection from hardwired disposition to behavior. And sometimes it takes the form of a more mediated connection, from selection-favored capacity to complex mental state to behavior. The response we have to a smiling baby falls in the first category, and the "good Samaritan" impulse falls in the latter.

The view at the other end of the spectrum holds with the (relative) autonomy of human thought and action. Human beings are natural biological organisms, to be sure, and our mental capacities are embodied in neural circuitry that has a specific evolutionary history. But what evolution provided us was an all-purpose "reasoning, acting, interpreting" machine that is capable of creating and embodying all cultural and behavioral systems. Much as a computer can embody any algorithm (program), a human brain can incorporate any system of cultural rules. Much as a human child can acquire any human language, so too any human child is a voracious "culture-acquisition device," primed to absorb the cultural rules and meanings around him or her. And once absorbed, it is the cultural program rather than the evolutionary instincts that rule behavior.

These are the polar views of the relation between evolution and culture. I think philosophers and anthropologists may prefer the second story over the first -- philosophers because it creates space for an all-purpose reasoning engine and anthropologists because it gives maximum autonomy to the symbolic and normative workings of freely created culture systems. For both there is the idea that humanity has kicked away its biological origins and limitations. And both are reflexively opposed to the apparent reductionism of the first position.

It seems to me that there is a sturdy intermediate position that incorporates some of both extremes and does a superior job of capturing the truth about human behavior and mind than either. Certainly human cognitive and behavioral capacities have an evolutionary history. But equally, it is plausible that there is a great deal of plasticity and multiple-realizability that has been built into these systems -- with the result that there is no one-to-one relationship between biological origins and current behavioral patterns. Culture is a powerful intervening structure.

Concerning the first point: the evolutionists are surely correct in believing that there is a great deal of brain structure that is responsive to the fundamental situations of human sociality -- family relations, cooperation and competition within small groups, and coordination. These elements of human daily life are too ever-present and too consequential not to have had implications for the evolution of the brain. Moreover, we know that there are highly evolved neural systems for non-social activities and challenges -- finger dexterity, for example, or simple problem solving. And, finally, we have the example of language, which involves both the kinds of latent linguistic structures that Chomsky postulates and the universality of application that results. So it would be surprising if evolution had not shaped the brain around these features of the human condition.

So acknowledging the likelihood of neural structures specific to social life seems pretty compelling. But what specifically? Almost certainly not determinate behavioral routines or dispositions. We surely don't have a gene for "promise-keeping". More credibly, we may have an abstract behavioral disposition for generalized reciprocity; and this may be invoked by a particular cultural system and set of value specifications that give a concrete moral motivation to keep one's commitments and promises.

This is where another important stylized fact about human society comes in: behavior differs widely and persistently across societies, and the best explanation of that fact is the causal efficacy of cultural and value systems that are reproduced within communities of human beings.

We know that those normative and symbolic systems are somehow embodied in persistent human neurophysiology, since all psychological states depend on the brain.  But from the variety of human symbolic, cultural, and normative systems we also know that the neurophysiology that underlies culture necessarily possesses a high degree of plasticity.  Along with the sociobiologists, we can look with favor on the notion that there may be important and contingent features that all human culture systems possess -- at some level of abstraction -- that are the result of constraints in the brain created by our evolutionary history.  But along with the cultural autonomists, we can work on the basis of the hunch that the human brain embodies enough plasticity and capacity for learning to make the role of culture and social norms a credible source of behavioral variation.

(These topics have been considered in earlier posts on human nature (link) and moral psychology (link).)

5 comments:

jon said...

The disciplines you cite are not polar opposites. They are simply asking and attempting to answer different questions. Obviously there are areas of overlap. In the overlap areas, there can be a synergy between the disciplines.

I don't think you are properly characterizing the sociobiology perspective. Sociobiology uses the work of philosophers and theologians as a way to validate their models and find inconsistencies that need to be addressed.

Just as in the past, religion and philosophy regarding creation have been informed by investigations of archeology and earth history, so too does sociobiology provide new areas for philosophy and other social sciences to explore. The problem for philosophers is that paradigm shifts can require extensive reworking of philosophy.

There is a need for religion and philosophy to incorporate the new findings of sociobiology regarding human culture and evolution. There is too much tendency to simply argue against old paradigms that have been superseded.

Peter van Maanen said...

Super Interesting Stuff. Thanks a million.

One such debate on culture vs. nature is the extent to which we are disgusted by feaces. Mary Douglas says it's cultural ("matter out of place", as a result of arbitrary catagorizations made by humans). Valerie Curtis argues it's evolutionary biology (she argues that hygiene behaviour and disgust predate culture and so cannot fully be explained as its product).

I would be grateful if you could shed your light on this issue. It is critically important in light of the promotion of sanitition (worldwide 1,2 Billion people still practice Open Defacation) i.e. how you promote it would depend on the mechanism underlying digust?

The article in which Curtis lays out her argument against Mary Douglas is found here:

Curtis, V., de Barra, M. & Aunger, R. 2011 Disgust as
an adaptive system for disease avoidance behaviour.
Phil. Trans. R. Soc. B 366, 389–401. (doi:10.1098/
rstb.2010.0117)

Peter van Maanen

Peter van Maanen said...

Super Interesting Stuff. Thanks a million.

One such debate on culture vs. nature is the extent to which we are disgusted by feaces. Mary Douglas says it's cultural ("matter out of place", as a result of arbitrary catagorizations made by humans). Valerie Curtis argues it's evolutionary biology (she argues that hygiene behaviour and disgust predate culture and so cannot fully be explained as its product).

I would be grateful if you could shed your light on this issue. It is critically important in light of the promotion of sanitition (worldwide 1,2 Billion people still practice Open Defacation) i.e. how you promote it would depend on the mechanism underlying digust?

The article in which Curtis lays out her argument against Mary Douglas is found here:

Curtis, V., de Barra, M. & Aunger, R. 2011 Disgust as
an adaptive system for disease avoidance behaviour.
Phil. Trans. R. Soc. B 366, 389–401. (doi:10.1098/
rstb.2010.0117)

Peter

jkinst said...

The biological foundation for reciprocity (and ultimately, empathy) you seek can be found in the discovery of the mirror neuron system. See this pdf link. (If you can't connect to it, send me a reply comment and I'll email you the pdf.)

Interestingly, the dysfunction of this system is being researched as a possible basis for autism.

bobsnodgrass said...

I think that Wilson and Sociobiology are a historically important digression. Wilson was and is an insect biologist of the pre-genomic era. His famous Sociobiology: The New Synthesis stirred up controversy, including fierce attacks in the New York Review of Books, led by his Harvard colleagues Gould and Lewontin, who accepted many of Wilson’s premises, but exaggerated his support for genetic determinism.. Many liberal or leftist groups objected that gene-centered theories of behavior neglected social forces, inequality, etc. The Bell Curve, by Herrnstein and Murray, was a simplistic view of intelligence the factors that determine intelligence. Few brain scientists take Wilson, Gould (he’s dead) Lewontin, Herrnstein (also dead) or Charles Murray seriously today , although all made valid points. Four were Harvard Professors.

Heredity looks far more complex today than it did in 1975 or 2002 when some science journalists (Robin McKie) crowed that the human genome project showed us cures for many problems. That enthusiasm was premature. The interaction of heredity and environment is much more complex than appreciated in 2000. Humans have only about 22,000 genes, not many more than mice, less than rice. Each gene codes for a protein (occasionally more than one); proteins are almost constantly modified by post-translational processes like phosphorylation and acetylation. The human proteome, all the proteins that humans may produce and harbor- may exceed 500,000. Furthermore diet, infection and environmental stresses alter these processes. We are influenced by the billions of bacteria that live in and on our bodies- change the biome and you change us. Symbols certainly influence human behavior, many become enraged if flags, holy books etc. are destroyed. Genes don’t tell us which symbols are important.

It’s outmoded to speak of nature versus nurture. Poor children start school at considerable disadvantage –more likely to be exposed in utero to malnutrition, infection and toxic influences, their vocabulary is much smaller than that of children from privileged homes and it’s harder for them to be still in class. Some are rescued by personal interest of teachers, no question, but many drop out of school and are marginally employable in adult life. As a group they start out with a handicap, surmountable with personal effort and expensive adjustments. Many cultures and societies aren’t willing to assume that extra expense. Some effects of prenatal infection and toxicity are irreversible.

Like all animals, humans have been shaped by evolution. It gave us strong in-group loyalties, suspicion of outsiders and willingness to fight them (other humans were more dangerous to our hunter-gatherer ancestors than were tigers and snakes). It gave us intentionality- if we hear a noise, we assume that a sentient creature caused it, directly or indirectly. We quickly and wrongly detect patterns in random numbers or noise. Evolution produced a species that is always at war. Under stress, we are prone to quick binary decisions, for us or against us. This is shown by gambling behavior, which is amenable to experimental study. When tired or angry, we gamble less skillfully. Professional gamblers, card-counters for example, learn to enhance their memories and control their emotions. Those who are good at this are surely genetically different from others who try and fail. However, their genes are only part of the story.

Curious that your commenters focus on things such as fecal pollution of water supplies (undesirable but not in the top 20 world problems) and simplistic views of autism. Humans need to believe and seek simple answers. Only with difficulty can we be educated away from these biological tendencies. This issue- how evolution shaped us for primitive life but not modern life is discussed in a recent book by Nobel Laureate Christian de Duve, one of several great European scientists who came to the Rockefeller Institute after WW II. The book is called Genetics of Original Sin- not a final understanding, but worth reading.