Dad's not lost: but his steadfast refusal to ask for directions—despite the jokes—need not be explained as an evolutionary trait of the human male

Deborah M. Gordon

Why Men Won't Ask for Directions: The Seductions of Sociobiology by Richard C. Francis Princeton University Press, 2003, $29.95

   Here we are in our car
   We've been driving ever so far,
   We've been circling round and round,
   Shall I tell you what we've found?

   Dad's not lost,
   No he's not,
   This is Daddy's favorite spot....

--"Dad's Not Lost" by Tom Paxton

Everyone knows the stereotype: Even when lost, men grimly drive on without asking for directions. Evolutionary psychologists would like to explain this behavior by appealing to the romantic lives of ancient hunter-gatherers and, even further back, to the hippocampus of small rodents. The analogy between lost men and lost voles may be silly, but there seem to be intriguing links between human and animal behavior. In Why Men Won't Ask for Directions, Richard C. Francis suggests that physiological explanations of behavior--about how brains work--are often more informative than accounts of why the behavior evolved.

Evolutionary psychology, which focuses on the evolution of human cognition, emerged in the 1980s out of sociobiology, a perspective that encompasses all behavior. Both sociobiology, which the evolutionary biologist Edward O. Wilson of Harvard University introduced in the 1970s, and evolutionary psychology adhere to the idea that every characteristic of every species is adaptive that is, each characteristic has enhanced reproductive success. Applied to explain the evolution of human behavior, the idea proceeds with appealing but misleading simplicity: Animals are depicted as doing something people also do. Next comes an account of the evolutionary advantage of the behavior for the animals. The conclusion is that it is natural, and therefore inevitable, for people to behave that way, too.

Ever since sociobiology was introduced, critics such as the the late Stephen Jay Gould and evolutionary biologist Richard C. Lewontin of Harvard University have pointed out that the basic reasoning of sociobiology and evolutionary psychology relies on mistaken evolutionary thinking. Not all characteristics of organisms, the critics note, come about as a result of natural selection. Before natural selection can operate, there must be some original variation among individuals in a trait, such as good versus poor spatial ability. Furthermore, the trait must be genetically inherited, and one or another version of it must enable some individuals to reproduce more than others. But there are plenty of traits around today that don't satisfy those criteria. Some traits have simply accompanied other traits that natural selection did favor, some are still hanging around as a result of a related trait in some distant ancestor, and some may persist purely by accident.

The most general objection to the idea that all traits are adaptive is that it results in stories about evolution that cannot be proved wrong, lf someone develops a good reason that natural selection led to a certain trait, the explanation may be accepted merely because it is plausible or comforting or clever, lf someone else gives a good counterargument to the explanation, a different adaptive reason can always be invented.

Critics of sociobiology have also pointed out another problem: the difficulty of establishing genetic inheritance of a trait. The action of genes depends both on the development and the environment of the organism. Behavior, furthermore, is social, developed in the context of" our interactions with others. Children imitate the behavior of the adults they live with, and everyone modifies behavior according to circumstances. A man might be willing to ask for directions at some times but not at others. Now, in Why Men Won't Ask for Directions, Richard C. Francis takes on evolutionary psychology and sociobiology from a new perspective--as a neurobiologist. He describes accounts of how sexual behavior works--particularly the neural and hormonal processes involved in the behavior--to rebut simple adaptive explanations for its evolution. He contrasts questions about what goes on inside an animal's body with questions about why natural selection favored a certain behavior. Francis shows that the answers to the "why" questions of evolutionary psychology ignore plausible, alternative "how" explanations.

Each chapter of the book describes one aspect of sexual behavior, outlines the adaptive explanation for it, and then offers a different account, on the basis of the physiology behind the behavior. Francis often argues that a particular behavior is a consequence of bodily processes rooted in evolutionary history, processes already in place when the behavior arose. Some sexual behavior, for instance, is a consequence of ancestral physiological pathways, rather than an innovation selected for its own sake.

Why, for example, do women have orgasms? According to the convoluted stories of evolutionary psychologists, because sperm enters the uterus more efficiently during orgasm, it is adaptive for women to be able to influence whose sperm can fertilize an egg, which they can do by choosing with whom they have an orgasm. Francis then describes an alternative explanation for female orgasm suggested by Elisabeth Lloyd, a philosopher of science at Indiana University in Bloomington, and others. Their idea is to look at the constraints imposed by development: the clitoris is derived from the same ancestral genitals as the penis. Natural selection for the ejaculation of sperm has favored the male orgasm, and having a clitoris leads, as does having a penis, to orgasms.

Most examples in the book are about animal, not human, behavior. (Francis's own research has focused on the astonishingly varied and flexible sexual behavior of fish.) He explains why fish change sex, and how some cichlid males can change from being small males without territories to large, dominant males with territories, and then back again. Those changes are probably not determined by natural selection on territorial behavior, Francis explains. Instead, they can be traced to the gonadotrophin-releasing hormone (GnRH) and its effects on the brain and body.

In another chapter Francis outlines research on sex differences in spatial ability, which investigators have studied in many animals, including kangaroo rats, voles, and people. The studies have discovered that males do better than females in various tests of spatial ability (though Francis argues that the data on people are dubious). In kangaroo rats and some vole species, investigators have found that male brains have a slightly larger hippocampus. Evolutionary psychologists maintain that natural selection has promoted a large hippocampus in male voles and kangaroo rats because spatial ability provides more reproductive advantages to males, who move long distances to mate, than to females, who stay home and let the males come to them. But, Francis reasons, in rodents the hippocampus is the site of GnRH production. To develop male gonads, a male must develop a larger hippocampus as well. Thus hippocampus size is related to sexual development, not to navigation, and there is no reason to imagine that selection on spatial ability has favored the large hippocampus of male rodents.

For some kinds of sexual behaviors, Francis combines physiological and adaptive explanations. He traces the weird sexual anatomy of female hyenas, whose clitoris looks like a penis, back to selection for female dominance. Female dominance, he notes, may be adaptive among hyenas, and selection for dominance would select for unusually high levels of androgen hormones in the developing female fetus. The female sexual anatomy thus need not be adaptive at all; instead, it probably originated as just a by-product of high female levels of androgen.

Francis gives a similar explanation for the exceptional mimicry of mockingbirds, suggesting that mimicry itself was not favored by natural selection. Mockingbirds belong to a lineage of birds that learn new songs throughout their lives. In some members of the lineage, males learn the song to which females are most receptive. Mockingbirds share with the rest of their lineage the neurological structures that make this learning possible. Francis suggests that in mockingbirds, this capacity leads to learning all the time, not just during mating behavior.

Francis is at his best when explaining physiological processes: his explanations are clear, straightforward, and step by step. In one section titled "Testosterone Rex," he outlines the effects of testosterone on the brain. In a few pages he debunks the idea that testosterone makes men behave as they do. He notes that the action of testosterone actually depends on its access to the brain's receptors for estrogen. And its action, in turn, depends on which genes have been turned on during early development. "Testosterone itself does not organize anything," he concludes:

The credit for the organizing that gets done as a result of testosterone's organizing effects should go primarily to the target tissues.... Next in importance, if we are ranking the developmental actors with respect to the magnitude of their causal role, are the androgen receptors. Testosterone comes in a distant third.

The descriptions Francis offers of animals and their behavior are vivid. Naked mole rats, he writes, are "shaped like late-season yams that have begun to sprout.... They seem to have been plucked from the womb much too early and then freeze-dried." His sarcasm is usually lighthearted. In what Francis calls the "Fred and Barney" story--the names refer to characters in The Flintstones--he recasts the account of the behavior of our hunter-gatherer ancestors invoked by evolutionary psychologists: the men go out hunting while the women stay home cooking and cleaning. The story is supposed to explain why men don't ask for directions: the idea is that women back then strongly preferred sexual partners who didn't get lost on the hunt. If sons inherited the spatial abilities of their fathers, and women persisted in this preference, not getting lost would increase--until somehow, now, men prefer not to appear lost. Along with this far-fetched story, the imagined lives of Fred, Barney, and their friends have also been invoked to explain, Francis writes:

Why we are so prone to kill each other and why we die for each other, why we exhibit fidelity to our mates and why we are adulterous, why we court and why we rape, why we are doting parents and why we commit infanticide, why we are ethical creatures and why we are sociopaths, why we have rock stars, why we have art, why we have religion, why we have language, and why we wage war.

All this may seem a heavy burden to put on Fred and Barney.

Francis's emphasis on "how" rather than "why" questions points to the direction in which evolutionary biology will move. As more is learned about how organisms work, explanations based on physiological and ecological processes will replace hand-waving stories about how natural selection might have worked.

But I think Francis concedes too much when he accepts an adaptive explanation, if plausible, as probably correct. Empirical testing of evolutionary hypotheses is difficult, but not impossible. At least sometimes, it is already possible to do more than decide which explanation is more appealing. Research in evolutionary ecology can demonstrate how natural selection is acting now. The hope is that the more data available on the ways natural selection is currently working, the more realistic will be the stories of how it happened in the past.

Unfortunately, only the choir--people such as Gould, Lewontin, or Lloyd--seems to hear the preaching by critics of sociobiology and evolutionary psychology. It is hard to explain why--in spite of so much intellectual energy devoted to demonstrating the mistakes of sociobiology and evolutionary psychology--the scientific rebuttals have had so little effect. Simplistic evolutionary explanations seem to crop up like a pernicious fungus around every new discovery in behavioral science. Does the persistence of adaptive accounts of human behavior merely reflect a collective fondness for explanations that are easy to understand, and comfortable because they justify the status quo?

Francis offers a different reason for the current addiction to adaptive explanations. He suggests that the need for "why" answers is analogous to paranoia, to a delusional belief in the operation of an external force. Just as the paranoid thinks someone is always out there, trying to hurt him, so evolutionary psychologists think something is out there, making everything happen for a reason. That belief comes close to religious faith, and in biology Francis traces this belief back to William Paley, the nineteenth-century theologian who argued, against Darwin, that God, rather than evolution, creates species. Perhaps, Francis suggests, evolutionary psychology is best understood as religious faith dressed up as science.

DEBORAH M. GORDON is a professor of biological sciences at Stanford University and the author of Ants at Work: How an Insect Society, Is Organized (Norton & Company, October 2000).

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