Fish gotta swim. Birds gotta fly. And people, it seems, gotta concoct a colossal array of cultural practices, group affiliations, and ethnic identities.
Over tens of thousands of years, we have acquired a special aptitude for tailoring ideas and innovations to the shifting needs of such groups, then passing the finished products on to the next generation. And in no time at all, on an evolutionary scale, urban societies and political states have become commonplace. Their astounding achievements and horrifying failures amass at an ever-quickening, often overwhelming pace.
Modern civilization's paradoxical nature is expressed in the flexible adage, "We can send a man to the moon, so why can't we get rid of poverty (or stop the slaughter in Bosnia, or. . .)?"
An evolutionary process unique to our species has molded societies capable of shooting astronauts to the moon and millions of designated enemies to death, assert Peter J. Richerson of the University of California, Davis and Robert Boyd of the University of California, Los Angeles. Cultural highs and lows alike spring from the human facility for coalescing into social units that extend far beyond family and friends, the two anthropologists argue.
In these assemblies, genetically unrelated folks band together by adopting cultural and ethnic practices that elicit mutual goodwill and good samaritanism. In contrast, small groups hold together through the return of favors between individuals and threats of punishment for selfish misdeeds.
Large cultural congregations dance to a peppier evolutionary tune than the traditional Darwinian waltz, in which genetic traits useful to a species slowly move to center stage, according to Richerson and Boyd. Instead, ideas and behaviors that give some cultural groups a survival edge over rival groups jitterbug to prominence, sometimes with a push from innate human instincts and sometimes on their own.
Richerson and Boyd's approach builds on the proposal-first described by Richard Dawkins of Oxford University in England-that cultural evolution occurs through the widespread imitation of new ideas, fashions, and other innovations, known collectively as "memes."
"Only in the last few millennia have human societies begun to exceed, in numbers of individuals and degree of complexity, the societies of ants, termites, and corals," Richerson contends. "What's novel in the human case is our propensity for group selection driven by a cultural inheritance system that operates alongside and in interaction with genetic evolution."
In this scenario, certain cultural groups developed ideas that yielded organizational advantages over competing groups. Unprecedented levels of cooperation among hordes of genetic strangers then resulted in ultrasocial institutions and societies extending far beyond family and friends, argue Richerson and Boyd.
They presented their latest take on the evolution of ultrasocial groups in July at the annual meeting of the Human Behavior and Evolution Society in Santa Barbara, Calif.
The roots of cultural group selection theory extend back at least 15 years. New support for the concept has emerged at the same time that scientists have taken increasing note of genetic group selection, a related but separate process (SN: 11/18/95, p.328). The latter theory posits that natural selection sometimes preserves inherited physical and psychological traits that aid groups of organisms, even at the expense of individuals in those groups.
Cultural group selection represents an alternative to traditional notions of culture. Social scientists have long assumed that people living in different parts of the world fabricated unrelated cultural systems mainly in response to local circumstances. Most theories assume that a small number of genetically ingrained instincts, such as the hunger and sex drives, spawned a bevy of unique cultures throughout the world.…