the evolving mind

[O]ne can prove the “naturalness” of almost any social pattern by selecting the appropriate species. The variety is immense. A strong mother-offspring bond is found in all primates; beyond this, virtually everything exists, from monogamy to promiscuity, from despotism to egalitarianism.
- Frans de Waal (1)

Thanks in a large part to a copious quantity of synapses – gaps between nerve cells – behavioral plasticity is a feature that blossoms from monkeys to Homo sapiens. Rather than a mono-function corkscrew, human nature is a Swiss Army knife. Any blade currently manifest, endowed in us by “nature,” is one nurture has extended. Plasticity in the brain translates into a great range of potential behaviors and thus flexibility in how an individual or group can adapt to its environment. And environments change.

Are we by nature aggressive apes or peaceful paisanos? It depends. We must look to the when and where to best answer that question. And we should remember that just because our kind presently seems one way, or in the past was another, that doesn’t mean either is more natural and thus correct.

Without gaps in the “wiring” of our brains, culture would be impossible. There would be but a single flavor of human being. Yet, fortunately or our adaptability, but frustratingly for our understanding, that isn’t the case. And it hasn’t been for millions of years. Primates are especially adept at behavioral flexibility. Gorillas and chimpanzees choose from a menu of behaviors, some of which – as we now well know with chimps – have been passed from one mind, one generation, to another. Digging for termites, using stones to open nuts, these are not hardwired tricks but acquired behavioral traits. (2)

So if we expect one species to stand up and declare itself as the perfect representative for what it means to be of genus X, family Y, and/or order Z, we are mistaken.

Among species in the same genus there is great variability. “Instead of considering one species as a prototype of how monkey groups are organized, we are beginning to see the incredible contrasts among species. Without exception, members of the genus Macaca establish clear-cut hierarchies, but the extent to which they follow their system is quite variable.”(3)

That caveat disclosed, we mustn’t throw up our hands and claim a philosophical agnosticism about the origin and development of human nature. An obstacle to note and work around, yes — an impassible dead-end, no.

With caution and diligence we can find real associations in the nature. For example, it has been established that serum level of testosterone is linked to aggressive and sexual behavior. (4) Whether rat or rhesus monkey, testosterone likely plays a key role.

The more brain plasticity and behavioral flexibility a species shows, the more important it becomes to recognize the specific when and where some part of a species’ nature becomes manifest. Nature and nurture are joined at the hip, so the reverse is also true. Without a nature to act upon, nurture is an inert concept. External influences act not by magic but by triggering internal mechanisms. I can recall a number of animal experiments in which, for example, a stampeding bull is stopped in its tracks by the flipping of a switch that stimulates a particular region of the brain. Or in which a submissive ape suddenly turns aggressive and vice versa.(5) Lacking an amygdala, no sight, sound, scent or artificial electrical stimulation could arouse or attenuate those behaviors

More than any other species, our kind is tremendously responsive to its environment. Soccer game hooligans and voluntary crews for Habitat for Humanity are equally representative of our nature. Simple answers may be much more appealing than the complex, but if we truly want to understand, patience is the blade we must unfold.

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(1) de Waal, F. Peacemaking Among Primates, Harvard University Press, Cambridge, MA, 1989, p.30
(2) Jolly, A. Lucy’s Legacy, Harvard University Press, Cambridge, MA, 1999, p.178
(3) de Waal, F. Peacemaking Among Primates, Harvard University Press, Cambridge, MA, 1989, p.168
(4) Thompson, J. G., The Psychobiology of Emotion, New York: Plenum, 1988, p.55
(5) Bourne, H., The Ape People, New York, Putnam, 1971

[this post first appeared here: http://almightyalpha.blogspot.com/2008/01/gaps-in-brain-jack-of-many-trades.html]

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