RE: Geoff Miller’s book The Mating Mind
An incredibly smart man just got around to taking some condensed notes (i.e., copying the passages that most resonated with him to a file).
He thought these excerpts might interest me, even if they’re a little disjointed pulled from the context. I wanted to share them with you people. I DID NOT COME UP WITH THESE NOTES MYSELF, a smart friend took these. You can tell I didn’t write it anyhow, since there is NO cursing.;)
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Sexual selection often creates an evolutionary positive feedback loop that is highly sensitive to initial conditions. It therefore tends to produce extravagant traits that have high cost and complexity, yet these traits are often unique to one species, and absent in closely related taxa. By contrast, natural selection for ecological utility tends to produce convergent evolution, where many lineages independently evolved the same, efficient, low-cost solutions to the same environmental problems. The human brain fits this profile of sexually selected ornaments.
The book’s theory of mental evolution is more testable than most, because the heritable sexual preferences of our ancestors are probably still manifest in modern mate choice, so they can be assessed as selection pressures independently of the courtship adaptations they are posited to have favored.
Even relatively simple nervous systems (e.g., insects, fish, frogs) suffice for mate choice — but that the more complex an animal’s brain, the more intelligent its mate choice could be. As mental complexity increased, the discriminatory power of mate choice would increase, so sexual selection would command ever more importance in evolution, reaching its zenith in human evolution. Darwin did not attempt a one-way reduction of psychology to biology, but saw psychology as a driving force in biological evolution.
In the 1970s there was a runaway revival of mate choice theory in evolutionary biology. Yet this revival has gone largely unnoticed in mainstream psychology, neuroscience, and the social sciences, which still view survival of the fittest as evolution’s bottom line, and which therefore have trouble seeing any evolutionary rationale for those aspects of human nature most concerned with self-ornamentation, display, status, ideology, fashion, and aesthetics.
Human brains make particularly good fitness indicators because their growth depends on about half the genes in the genome, thereby summarizing a huge amount of information about mutational load. Brains are also good indicators of nutritional state and general health, because they have such high energetic costs.
Species-unique courtship adaptations are far outnumbered by the psychological adaptations for social intelligence, foraging, predator avoidance, etc., shared with other primates. Yet we still need some explanation of why small, efficient, ape-sized brains evolved to huge, energy-hungry handicaps spewing out useless behaviors such as flirtatious conversation, music, and art.
Sexual selection works like a venture capital, extending a line of reproductive credit to potential useful evolutionary innovations before they show any ecological profitability. The obsession with survival selection is analogous to the early twentieth century corporate session with production as opposed to marketing and advertising. Business has had its marketing revolution in the last half-century; it is time for evolutionary psychology to recognize that creative social behavior is to the opposite sex what products are to consumers.
The bower is part of the bowerbird’s extended phenotype — a genetically evolved display constructed outside the body. Human aesthetic behavior also functions as an extended phenotype. The idea that beautiful artifacts carry information about the fitness of their makers makes sense. An artist’s manifest virtuosity (manual skill, access to rare resources, creativity, conscientiousness, intelligence) is the major criterion of beauty in most cultures. This view was eclipsed in aesthetic theory by 20th-century modernism (which rejected the concepts of the beauty and virtuosity), but remains relevant to most popular culture, interior design, folk art, craft, and fashion.
The hidden genetic benefits of altruism could have been reproductive: conspicuous magnanimity and other moral behaviors became sexually attracted because they were good fitness indicators. Their reliability was guaranteed by the costs of altruism, under the handicap principle. Only the fit could afford to be generous.
Almost all complex acoustic signals in other species evolved as courtship displays through sexual selection: frog croaks, bird song, whale song, etc.. Human verbal courtship serve an analogous function, with mutual advertisement of capacities for speaking, listening, thinking, remembering, storytelling, and joke making.
Once language evolved, much more of our mental life became subject to sexual selection. Verbal courtship could reveal whole new areas of mental functioning — personality, intelligence, beliefs, desires, past experiences, future plans — that are hidden in the more physical courtship of other species. As language gave a clearer window on the mind, the mind became more easily shaped by mate choice. This sexual selection feedback loop between mate choice, language ability, and creative intelligence was probably the mainspring of human mental evolution.
Since vocabulary size is highly correlated with general intelligence, and is highly heritable, it appears to function as a reliable indicator of heritable mental fitness. People are generally unaware of their sexual preference for large vocabularies, but assortative mating for vocabulary size is higher than for almost any other mental trait.
Primate and human neophilia is especially strong. Partners who offered more cognitive variety and creativity in their relationships may have had longer, more reproductively successful relationships. A good sense of humor is the most sexually attractive variety of creativity, and human mental evolution is better imagined as a romantic comedy than as a story of disaster, warfare, predation, and survival.
Sexual selection for creativity undermines some of the evolutionary epistemology claims about the reliability of human knowledge. Whereas natural selection might tend to favor minds with accurate, survival-enhancing world models, sexual selection might favor minds prone to inventing attractive, imaginative fantasies — as long as fantasy-invention ability remains a reliable fitness indicator. Sexual selection can explain why most people prefer fiction to nonfiction, religious myth to scientific evidence, and political correctness to intellectual coherence.