The Evolution of Culture in Animals
Man, the Promising Primate
The female mason wasp, Monobia quadridens, excavates a broad chamber by digging a long tube into the pith of trees and stems. She deposits a series of eggs in the tube, starting at the bottom and separating each egg from the next by a curved mud partition. The partitions are shaped with their rough and convex side toward daylight and their smooth and concave side toward the cul de sac at the blind end of the chamber. The larvae feed and pupate within their chambers, which the mother has provisioned with food. When the young adults emerge, they crawl toward freedom by chewing through the rough, convex sides of the partitions. If the partitions are experimentally reversed, so that the rough and convex sides now point toward the cul de sac, the emerging adults cut their way into the stem, pile up at the blind end of the tube, and eventually die. Apparently, the mason wasp has evolved a rigidly programmed rule of behavior: cut through the rough and convex side of the partition. In nature, obedience to this rule always leads to daylight. If a human experimenter intervenes to reverse the partitions, the wasp cannot accommodate and digs to its own death, steadfastly obeying its unbreakable rule.
What the wasps lack (as Bonner tells this arresting story)—and what human beings possess in unparalleled abundance—is the common theme of both books: flexibility in behavioral response. Bonner defines culture as “the transfer of information by behavioral means,” and structures his fascinating book as a survey of culture in the animal kingdom, marching up the venerable chain of being toward bigger brains, increasing behavioral complexity, and freedom from rigid genetic programs specifying “single response behaviors.” Wilson identifies flexibility—that is, freedom from genetic programming of specific behaviors—as the key to our evolutionary promise; he traces the origins of human culture to the structural and nongenetic (but biologically based) rules that we follow in establishing systems of kinship.
Human flexibility has at least three complex and interrelated sources. First, we possess a brain much larger, in proper relation to the size of our bodies, than that of any other animal (except the bottle-nosed dolphin). More circuitry gives any computing machine a capacity for flexible response that increases (indeed explodes) at a far faster rate than the growth of its material substrate. A simple machine can handle tic-tac-toe; complex computers may soon be giving chess grand masters a run for it. The metaphor is somewhat mixed, but it is an arresting thought nonetheless that our brains contain more information, in an engineer’s technical sense, than all the DNA in our genes.
Second, we have evolved our massive brains largely by the evolutionary process of neoteny: the slowing down of developmental rates and the consequent retention to adulthood of traits that mark the juvenile stages of our ancestors. We retain the rapid fetal growth rate of neurons well beyond birth (when the brain of most mammals is nearly complete), and end up with the bulbous cranium…
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