The Human Beast

Is sport a religion?

Nigel Barber, Ph.D. — Wed, 11 Nov 2009 13:41:54 +0000

Psychologists are closing in on the conclusion that sport has many of the same effects on spectators as religion does. Here is Daniel Wann [2001], a leading sport psychologist at Murray State University, and his co-authors:

The similarities between sport fandom and organized religion are striking. Consider the vocabulary associated with both: faith, devotion, worship, ritual, dedication, sacrifice, commitment, spirit, prayer, suffering, festival, and celebration. p. 198

It may seem odd, to equate religion with sport entertainment but it must be understood that prior to mass communications, religious ceremonies were a source of entertainment for ordinary people who rarely attended a theater or traveled to a sporting event. Sports and religion may get categorized separately but their intersection is difficult to miss.

As Wann and collaborators note, various scholars discuss sport in terms of "natural religion," "humanistic religion," and "primitive polytheism" pointing out that "spectators worship other human beings, their achievements, and the groups to which they belong." And that sports stadia and arenas resemble "cathedrals where followers gather to worship their heroes and pray for their successes." [Wann, et al., 2001, p. 200]

If ritual may be entertaining, then entertainment, as experienced in a sports stadium, may be ritualistic. Fans wear the team colors and carry its flags, icons, and mascots. Then there is repetitive chanting of team encouragement, hand-clapping, booing the other team, doing the wave, and so forth. The singing of an anthem at a sporting event likely has similar psychological effects as the singing of a hymn in church.

Given that sports entertainment has obvious similarities to religious rituals, it is reasonable to ask whether the connection between fans and their preferred sport has psychological effects that are comparable to religious experiences - effects that account for religion as a worldwide human adaptation.

Sports as a substitute for religion
As a group, sports fans are fairly religious, according to research. It is also curious that as religious attendance rates have dropped off in recent decades, interest in sport spectatorship has soared. Moreover, research has debunked several stereotypes about sports fans that seem incompatible with religiosity. Fans are not lazy, Nor are they particularly prone to violence. Male fans do not have bad marriages.

Some scholars believe that fans are highly committed to their favored stars and teams in a way that gives focus and meaning to their daily lives. In addition, sports spectatorship is a transformative experience through which fans escape their humdrum lives, just as religious experiences help the faithful to transcend their everyday existence.

From that perspective, the face painting, hair tinting, and distinctive costumes are thought to satisfy specific religious goals including identification with the team, escape from everyday limitations and disappointments, and establishing a community of fans.

So far, the transformative aspects of fandom are quite close to those associated with religion. Lest the fans become too smug, here is a socialist critique:

Shaped by the needs of capitalist systems, spectator sports serve vested interests as a type of "cultural anesthesia," a form of "spiritual masturbation," or "opiate" that distracts, diverts, and deflects attention from the pressing social problems and issues of the day [Wann, pp 201-202].

Of course, Karl Marx famously declared that religion is the opium of the people, Not all religions numb people to their social and moral responsibilities, however. On thinks of liberation theology in Latin America, for instance. No one ever claimed that sports had such redeeming qualities, however. According to one critic (Harris, 1981), "it has turned into a passion, a mania, a drug far more potent and widespread than any mere chemical substance." It is the new opium of the people.

Harris, S. J. (1981, November 3). Sport is new opium of the people. Democrat and Chronicle, p. 3B.
Wann, D. L., Melznick, M. J., Russell, G. W., & Pease, D. G. (2001). Sport fans: The psychology and social impact of spectators .New York: Routledge.

How much physical activity do we really need?

Nigel Barber, Ph.D. — Tue, 20 Oct 2009 13:27:11 +0000

There is a happy land in which obesity and heart disease are virtually unknown. That is the realm of subsistence humans who eat more than we do. Thanks to their active lifestyle hunter-gatherers are ideally lean, fit, and healthy (apart from ever-present animal attacks, parasites, and infections). How much exercise would we have to take to be as active as our foraging ancestors? How does this compare with medical advice about exercise?

Medical guidelines
Current medical guidelines identify a reasonable amount of exercise that can deliver substantial health benefits. In 1995, the American College of Sports Medicine (echoed a year later by the Surgeon General) recommended that adults should engage in moderate physical activity for 30 minutes each day. Moderate activity involves walking at three miles per hour, for example.

How close do the medical experts come to the physical activity level of people in subsistence societies? Fortunately anthropologists collect extensive information on the diet and food intake, as well as the body weights of their study populations. These data allow us to calculate how much energy a particular group uses on physical activity and to compare them with Americans.

How active are foragers?
Detailed research on two hunter-gatherer societies (or "foragers") allows us to calculate how active they are. These are the Ache of Paraguay and the !Kung of the Kalahari Desert in southern Africa. The !Kung are rather smaller (at about 100 lbs) and have comparatively low activity levels whereas the Ache are bigger (at about 130 lbs) and highly active thanks to their high birth rate.

A !Kung male uses about 2,200 (kilo)calories per day in total, almost exactly the same as a male office worker, whereas an Ache man uses some 3,300 calories in a day (1). Out of their respective total daily energy consumption, the !Kung use about 894 calories on physical activity (compared to 607 for office workers) whereas the Ache use a whopping 1772 calories this way.

Since the !Kung and Ache are so much lighter than Americans, it is important to take body weight into account. I did this by converting their energy consumption into number of miles walked (at a standard 3 mph) the point being that energy used in walking increases the more weight a person is carrying. Energy used for daily physical activity was equivalent to 10 miles walked for the Ache, 6.8 miles for the !Kung, and 3 miles for the Americans.

If Americans wanted to be as active as the !Kung, they would need to add the equivalent of 3.8 miles of walking to their daily activity. If they wanted to be as active as the Ache, they would need to hike 7 miles a day. Taking the average, if we wanted to be as active as foragers, we would add 5.4 miles.

Walking at 3 mph, this would take 1.8 hours. This is 3.6 times the half-hour the Surgeon General and other medical experts recommend.

Here we get to the military commander's problem. It is very easy to tell Americans to walk five miles per day. The commander charges over the top only to find there is no one behind him. It is true that most people would be a lot better off doing half an hour of moderate exercise daily compared to none. Yet, our bodies were designed for doing about four times this much activity and would likely be much healthier doing so.

Activity can be clocked up in many different ways, however, including the fidgeting typical of slender people (2). Or you can do something you enjoy.

An hour-and-a-half of shopping with a cart uses about the same amount of energy as walking 5 miles. Or an hour of digging in the garden. Or two hours playing music while standing. Or two hours of waiting on guests. Being as active as a forager is neither easy nor simple in the modern world but it might be worth the effort, mental as well as physical.

1. Cordoin, L., Gotshall, S. W., Boyd Eaton, S, and Boyd Eaton, S., III (1998). Physical activity, energy expenditure and fitness: An evolutionary perspective. International Journal of Sports Medicine, 10, 328-335.
2. Levine, J. A. (2003). Non-exercise activity thermogenesis. Proceedings of the Nutrition Society, 62, 667-679.

Moving Too Little or Eating Too Much?

Nigel Barber, Ph.D. — Wed, 23 Sep 2009 13:31:12 +0000

Who can forget the fight between gangly Ace Ventura and his diminutive opponent from the !Kung San tribe who substituted fierceness for stature? Jim Carrey is freakishly thin and fit in our society but his opponent benefited from the superb physical conditioning of all his tribe (pictured). No obesity there.

All diets assume that we Americans are overweight because we eat too much. Yet, the real problem is not over eating. We are overweight because we move too little.

That big picture often gets overlooked. This is unfortunate because you have to understand the problem before you can devise real solutions. Diets don't work because nutrition is not the main underlying problem. The key problem is inactivity.

The evidence is plain in every subsistence society
The transition to urban life is everywhere accompanied by soaring obesity rates and accompanying diseases such as diabetes, and high blood pressure. Urbanites sit around in offices much of the time and do not get enough exercise to regulate their body weight at a healthy level.

For highly active individuals, overweight is not a problem, however much they eat. In experiments where volunteers upped their food intake by 50%, there was no increase in body weight among physically active individuals ("non exercise" activity). Of course the inactive individuals put on plenty of weight.

Physical activity of any kind is capable of raising metabolism at rest and also the warmth we experience after a meal (thermic effect of food). A lot of food energy is thus spent in producing heat instead of getting stored as fat. This means that physically active people expend much more energy than that required to do the work of movement.

Because they are so much more physically active, people in subsistence societies have very low levels of overweight and obesity. The transition to an urban lifestyle can be devastating.

The star exhibit here are the Native American Pima of Arizona, one of the fattest groups of people on earth. When occupied as farmers, they were as skinny as other subsistence peoples. This phenomenon has often been attributed to genes but the Mexican Pima who are genetically similar, do not have a high incidence of overweight. Shockingly, the Mexican Pima eat significantly more than their overweight American counterparts.

The same paradox of the skinny peoples of the world eating more than the obese ones is found repeatedly. Among hunter-gatherers, such as the Ache of Paraguay, the average man, at 150 lbs weighs substantially less than the average American man but consumes 3,300 calories (i.e. kilocalories) compared to just 2,700 for the average American male.

How do the Ache manage to eat so much without getting overweight? The answer is that they are very active compared to us, using three times as much energy in physical activity as we do (about 1,800 calories compared to 600 for us). When we lead an active life, we are good at regulating our weight, regardless of how much we eat.

Farmers have long known that if you want to fatten a cow before slaughter the fastest method is by confining her in a small space with plenty of high-energy food. By restricting our own movement via a sedentary lifestyle we are doing the same to ourselves.

Can Brides Justify Losing Their Names?

Nigel Barber, Ph.D. — Fri, 18 Sep 2009 14:06:10 +0000

American men and women are equal under the law. Yet, when they enter a marriage contract, it is the women who give up their names. Men almost never do.

There are wrinkles in the story, of course. Some women keep their own names. Double-barreled names that join the surnames of bride and groom are becoming more common but they are more likely to be used by women than men. Even feminists have a penchant for adding the husband's name to their own.

Why are modern women so willing to give up their names, or to change them? Marriage is evidently perceived as an enhancement in social status for women. By changing her name, a woman advertises her success in crossing this social hurdle. If she marries up the social ladder, a women can even bump her social status up to that of her husband's family. This provides another motive for name changes.

There are several practical reasons why women might want to be married with a formal name change, even today. First, and foremost, perhaps, is the fact that by changing her name to that of her husband, a new wife acquires legitimacy for her children, including rights to child support and property inheritance.

Giving the husband's name to children implies that he is the father although there are many cases where that is untrue. Low confidence of paternity is a problem that is unique to men so that when a woman takes her husband's name, she is stating that he is the father of her children. Since there is no doubt about who is the mother of a child, there is less reason for men to take their wives' names.

Paternity confidence is far from being the whole story because there are many societies where women do not take their husbands' names, including many Islamic societies, Scandinavia in earlier centuries, Spain, Korea, and China, among others. Even if they do not change their names, there are other ways in which their marital status is publicized, such as by wearing wedding rings.

By assuming her husband's surname, either singly or in combination with her own, a bride is acknowledging the husband's paternity of any children. She is also making a statement about her social status in our society, given that single parenthood is much more common among the poor. Is she bragging about her success in having captured (captivated?) a marriageable partner? This feat eludes more and more women with the passage of time.

Apart from the social advantages of being married, it is very odd that so many women still adopt the husband's name when they marry. People who lose their names lose their identity. This happened during the era of slavery when captives were known by the surname of their owners. Why would anyone want to throw away their own identity and assume that of a husband?

It cannot be for convenience. Changing one's name on bank accounts and other official documents is quite a chore.

Another possibility is that marriage names are simply a way of keeping track of familial relationships - a social habit that gets passed down with the native tongue. Among English speakers, the wife generally gets the husband's name. among Spanish speakers, names of children often combine the names of both parents with a given name. It may be too cumbersome to add yet another name upon marriage.

Take your pick: social status; child support; inheritance rights, confidence of paternity, mindless tradition. Personally, I cannot understand why any person would voluntarily surrender his, or her, name at marriage. What is wrong with being yourself?!

Who really tells just-so stories, evolutionists or their opponents?

Nigel Barber, Ph.D. — Wed, 09 Sep 2009 14:00:37 +0000

Just-so stories were invented by British writer Rudyard Kipling. Writing for children, he devised amusing and quirky tales about how different animals acquired their distinctive features. The camel was given its hump by an evil spirit for refusing to work because the hump allows it to work for longer without eating, for instance.

Apart from their sheer silliness, the just-so stories differ from science because they are idiosyncratic. A different kind of story is told for each species. Darwin's contribution was to propose an explanatory theory that would work as well for one species as another.

The theory of evolution by natural selection is not just good for explaining why elephants have big ears, but can also explain the big ears of bats, or the small ears of moles. This is exactly the opposite of Kipling with his different "explanation" for every animal's peculiarities. Ironically Darwin's successors are frequently accused of telling just-so stories precisely when they are comparing humans with other species.

Why this happened is hard to be sure but it may well be an example of the Carl Rove effect. This evil genius overcame a weakness of his own candidate by projecting it onto the opponent. If George Bush sat out the Vietnam War while John Kerry served his country, then attack Kerry for disloyal conduct in the course of the war, as in the swiftboat ads.

Consistent with this thesis, one finds that all of the main opponents of evolutionary thinking tell just-so stories all of the time. This is true of religious fundamentalists because they separate humans from the rest of biology. It is true of Communists and socialists because they deny that inherited biological influences really matter in human affairs. Cultural determinists do Kipling all of the time invoking a distinct explanation for human behavior in different ethnic groups, different places, and different time periods

One example of a just-so story that I discredited earlier is the view that People of Scots Irish descent are infected with a "culture of violence," due to their herding antecedents. Another is Susan Brownmiller's thesis that men everywhere are inclined to rape women so as to deny them political equality. Ditto for Margaret Mead's tale that there are no sexual conflicts in Samoa . Or the argument that single parenthood is due to weak "family values" (see The Myth of Culture). Virtually every cherished theory in the social sciences is a just-so story.

I never thought about how shockingly inappropriate the just-so criticism of evolutionists is until I was personally accused of just this failing in a recent scholarly book on physical attractiveness penned by two social psychologists. Specifically, they attacked my suggestion that women today are attracted to moderately big, strong, and muscular male bodies partly because such men would have prevailed over sexual rivals in the evolutionary past.

The authors mistakenly conclude that because I do not have a time machine, I cannot draw any valid conclusions about our evolutionary past. They underestimate the power and subtlety of the comparative method that I used in my 1995 paper.

Instead of producing a quirky story that applies to just one case, my physical attractiveness paper discussed attractive human male bodily features in the same context as the antlers of deer and the colorful plumage of male birds (sexually selected traits that attract females).

A distinct pattern emerges for body size. Among species where males are larger, and stronger, than females this is also due to male-male sexual competition. Their bulk and strength are used to fight off other males so as to inseminate as many females as possible.

Is this a just-so story? No, because it can be, and has been, tested and verified repeatedly using modern data. In species with intense sexual competition, such as elephant seals, the male is very much larger than the female. Among various deer species, those that monopolize a large harem are very much bigger than females whereas smaller harems are associated with a smaller sex difference in size with monogamous deer being of the same size.

Because I considered many other species, I could be confident that the greater size and strength of men than women had to be due to sexual competition operating over many generations. Such generalizations lie at the heart of science. They are the opposite of just so stories that consider each phenomenon in isolation. We evolutionists are not the ones telling the just-so stories.

Is nature red in tooth and claw?

Nigel Barber, Ph.D. — Tue, 01 Sep 2009 13:32:37 +0000

Like sex, violence is popular in entertainment. It boosts TV ratings, helps to sell household products, moves video games, and books, and garners the attention of young people when all else fails. Nature movies get in on the act as well, reveling in the gory details of predators dismembering their prey. But is nature as violent as most people, including biologists, imagine? Or is it just that violence is what gets people's attention?

Huxley versus Kropotkin
Herbert Spencer's notion of nature being red in tooth and claw is a common position among leading Darwinists, including Darwin's bulldog, Thomas Huxley. Huxley wrote: "From the point of view of the moralist, the animal world is on about the same level as the gladiator's show. The creatures are fairly well treated, and set to fight, whereby the strongest, the swiftest and the cunningest live to fight another day."

Huxley had his critics. Alfred Russell Wallace, the co-discoverer of evolution concluded that . . ."the popular idea of the struggle for existence entailing misery and pain in the animal world is the very reverse of the truth. What it really brings about is the maximum of life and of enjoyment of life with the minimum of suffering."

This distinctly un-Western view was echoed by Peter Kropotkin who is thought of today mainly as a shaggy-headed anarchist but was a respected mainstream Russian biologist. Kropotkin believed that cooperation is normal in nature. In his book, Mutual Aid, he wrote: "If we resort to an indirect test and ask Nature: Who are the fittest: those that are continually at war with each other, or those who support one another? We at once see those animals which acquire mutual aid are undoubtedly the fittest."

Huxley seemed to have won the day. Writing a decade ago, Lee Dugatkin, an expert on animal cooperation, could proclaim: "While it probably pulls on our heartstrings to believe that the natural world is quite a cooperative place ... the literature on every sort of noncooperative act imaginable suggests that this view is naïve - nice in principle, wrong in fact."

And the final score is . . .
This confident assertion was shattered in 2005 by the publication of research that analyzed the field data on 60 species of primates from 81 different studies. The bottom line is that primates spend just 1 percent of their time being disagreeable and 9 percent of the time being nice (the other 90 percent of their time is spent in nonsocial activities). So the score is Huxley 1, Kropotkin 9!

Authors of the study suggest that aggression is so potentially costly it must be used sparingly. On the other hand it costs almost nothing to be nice. Being nice makes for poor entertainment, however, boring scientists and the public alike.

Why modern women behave more like men

Nigel Barber, Ph.D. — Mon, 24 Aug 2009 13:15:21 +0000

Women today behave very much more like men than their grandmothers. After all, they attend college to compete in careers (rather than to find a husband). They are interested in sex. They drink alcohol and do drugs. They are active in competitive sports, including as professionals.

Social scientists often attribute such profound changes to "sexual liberation" but this is really more of a semantic trick than a true scientific explanation. It is an exercise in circular reasoning. We should not be too surprised by that because virtually all so-called explanations in the social sciences follow a similar defective formula as I argue in scholarly detail in my recent book "The myth of culture: Why we need a genuine natural science of societies."

If women are behaving more like men and scholars attribute this to sexual liberation, we are entitled to be skeptical. It is tantamount to saying that women are now free to behave more like men because they are more free to behave like men (i.e., have been sexually liberated, or unshackled from feminine "roles"). We are in the presence of the Rumpelstiltskin effect - give the problem a name and it goes away.

It is all too easy to be a critic, of course. If one wanted to provide a real explanation for changing feminine behavior, what would this be? There are different possible levels of explanation but the most basic is biological. A lot of evidence is accumulating that the competitive behavior of men and women, just like that of other species is mediated by changing levels of sex hormones.

Using hormones as an explanation may seem far too simple, a case of biological reductionism run amuck. Ironically, hormonal explanations are never quite as simple as might be imagined for the simple reason that behavior affects hormones and hormones affect behavior in a never-ending chain of reciprocal causation. That is why hormones are such a valuable clue to understanding changes in gender-typed behavior.

This argument was advanced most explicitly by Anthropologist Elizabeth Cashdan of the University of Utah in a recent paper in Current Anthropology that is ostensibly concerned with changing female body shape. Cashdan believes that the optimal female body shape is not the hourglass figure of a Marilyn Munroe or a Scarlett Johansson with narrow waist and large breasts. In most societies, women actually have wider waists and such figures are more attractive to men in subsistence societies, such as the Zulu (pictured) where food is scarce and also in countries like Denmark and Britain where there is greater equality between men and women.

In societies where women are under pressure to provide for their children, increased testosterone production increases their stamina, strength, and competitiveness. However, along with stress hormones, testosterone also increases the amount of fat stored about the waist, thereby reducing stereotypical femininity of the figure.

Cashdan's results are mainly descriptive rather than statistical because she did not have a large enough number of societies to compare. My own statistical analyses of women's ideal figures as they vary from year to year in magazine pictures, also found that women subscribed to less curvy ideals when they entered higher education and careers in large numbers, see The Science of Romance: Secrets of the Sexual Brain. When they compete with each other for jobs, they are more interested in seeming competent than in looking sexy. During the 1950's, when women briefly reverted to marriage, rather than careers, a sexier figure was preferred in ladies magazines. This was the heyday of Jane Russell and Marilyn Munroe.

A boost in testosterone production thus helps explain why women not only behave more like men but actually develop a more masculine body shape. All of these phenomena fit together in a neat pattern whereby women change in ways that help them to succeed in different kinds of societies. Such a neat match between body and behavior (or phenotype) and what is required for competitive success is really an adaptation.

Adaptations are often thought of as lock-and-key type relationships between the phenotype and the function. The giraffe's neck is an ideal "crane" for reaching into tall trees, for instance. If the social environment is the lock, and female competitiveness is the key, then hormones are the locksmith grinding out women to succeed in many different societies. Of course, men have also begun to behave more like women, adjusting to their greater role in caring for children thanks to other hormone locksmiths.

Sex hormones and womanly passions

Nigel Barber, Ph.D. — Tue, 28 Jul 2009 14:14:25 +0000

In my last post, I pointed out that testosterone fuels the reckless sexual and aggressive behavior of young men and other male vertebrates. Recent research is closing in on sex hormones (androgens as well as estrogens) playing a very similar role for women.

The female hormone estradiol (a key estrogen) plays a role in dominance communication and physical aggression among primates. Recent evidence suggests that it stokes competition amongst human females. Women with a high need for power have higher estradiol levels in their blood. What is more, their estradiol level increases when they "win" a contest with another woman that is actually manipulated by experimenters and remains elevated for a day. Estradiol declines when they lose.

So far, it seems that estradiol plays a similar role in the competitive interactions of women as testosterone plays for men. Yet, there is little evidence that high-estradiol women are more aggressive in the way that high-testosterone men tend to be. Their other distinguishing features are that they tend to be physically attractive, to have tempestuous romantic lives, and to be highly competitive with other women (what might be called the Marilyn Munroe effect).

Patchy though this evidence is, it paints an intriguing picture of women as being affected by estrogens (i.e., estradiol) in much the same way that men are affected by androgens (i.e., testosterone). Yet, there is more. In addition to being swayed by womanly hormones, women are also affected by testosterone. This is normally thought of as a masculine hormone because it is present in much higher levels in males but it is present in women as well and affects both their competitive interactions and their sexual motivation which might help to explain why female sexual motivation is so different in various countries (as described in an earlier post).

Testosterone and womanly passions
Testosterone also plays an important role in the competitive interactions of female mammals, including primates. Testosterone is naturally present in women, being produced by the adrenal gland. It serves many different functions apart from sexuality and aggression. These include the growth of pubic hair, muscle development, fat deposition around the waist, and the organization of brain circuitry before birth.

Women with high testosterone levels describe themselves as being action-oriented, resourceful and powerful. Effects on physical aggression are unclear. Research shows that high-testosterone women are more competitive and more verbally aggressive, however. In experiments, women administered testosterone respond more strongly to angry faces. They also take bigger risks in a game of chance. Women who had been exposed to more testosterone early in development (as inferred from the relative length of the ring finger compared to the index finger) are more competitive, more assertive, and more socially dominant. Testosterone affects sexual behavior in women as well as men.

Small doses of testosterone are used to treat extremely low levels of sexual desire in women that compromises their sexual function and threatens their marriages. Experiments have shown that testosterone administration increases self-rated genital sensitivity and objectively-measured sexual arousal in response to an erotic movie. On the other hand taking contraceptive pills, which render testosterone inactive by increasing the amount of sex hormone binding globulin, reduces sexual desire, interferes with lubrication, and decreases sexual enjoyment.

Although psychologists are often wary of acknowledging that hormones play much of a role in human psychology or behavior, the evidence suggests otherwise. Like robins in the springtime, young men are more amorous and more reckless, so that they are more likely to break rules, drive dangerously, and get in fights.

What is sauce for the gander turns out to be sauce for the goose. Women are more competitive, more risk-taking, and more socially dominant, if they are affected by high levels of sex hormones (both estradiol and testosterone). Surprisingly, the hormone that plays the clearest role in female social competition, and in feminine lust, is not an estrogen, but an androgen - testosterone.

These phenomena turn out to have many practical applications. For instance, women have higher testosterone levels in societies where they compete with each other in the work place. This means that they are more sexually liberated and behave more like men in relation to drug use, reckless conduct, and crime. Indeed, their body shape becomes more masculine. More on this in a later post.

Sex, violence, and hormones

Nigel Barber, Ph.D. — Wed, 15 Jul 2009 13:55:45 +0000

When male robins enter the breeding season, their testosterone level rises. They become aggressive and amorous. Testosterone has remarkably similar effects on men.

This conclusion does not sit well with most psychologists. Psychology professors emphasize that whereas men with low testosterone levels are generally low on aggression and have a low sex drive, men who are high on testosterone may be neither aggressive nor randy.

Why are we so comfortable with assuming that other animals are controlled by their hormones whereas humans are not? The prevailing view is that human behavior is regulated by higher cognitive processes. Reason cools the blood, allowing us to take responsibility for our actions. This is an ancient philosophical formula that was most explicitly developed by French Philosopher Rene Descartes (1596-1650). Yet, even Descartes did not believe the rational soul was always in charge and accepted that there are times when humans are ruled by their passions.

Evidence that human behavior is partly governed by hormones is mainly restricted to correlations, which are not the same as causes. At least one experiment found that large doses of testosterone increased aggression but only for a small proportion of men. Young men who use anabolic steroids - a synthetic version of testosterone - are also more likely to be involved in violent crime. Taken together, such findings imply that high levels of testosterone can cause aggression in at least some men. Other evidence points in the same direction.

Young men experience peaks in criminal behavior and testosterone production at around the same ages. When they marry, men experience a decline in both testosterone production and criminal offending when compared with single men of the same age.

It seems that marriage has a civilizing effect on men because it reduces their testosterone levels. Of course it would be impossible to randomly assign some men to marry and others to remain single in order to test this hypothesis experimentally.

The next best thing is a natural experiment. When men divorce and begin dating again, their testosterone level rises, just as it does for male robins in the breeding season.

What is more, their involvement in violent crime increases. This is at least partly due to an altered lifestyle with more time spent staying out late at night in clubs and bars where single women are encountered. Increased alcohol consumption is a complicating factor as this clouds reason and impairs judgment.

As correlations go, the link between testosterone and violent crime is arguably as compelling as the link between testosterone and mating aggression for robins and other animals. Indeed, one can argue that most violent crimes occur because of reproductive competition (e.g., male-male assaults and homicides, domestic violence).

What about the link between testosterone and amorousness in the human male? Once again, the evidence is interesting. Male sexual desire is believed to peak in early adulthood at about the same time as testosterone peaks in the lifespan. Recent research also finds that testosterone levels increase when men encounter attractive women and engage in sexual intercourse.

Men are not the same as male robins, of course and you cannot really understand crimes of violence without also studying societal differences (such as the ratio of men to women), contextual factors (such as location relative to a bar), and behavioral issues (such as why someone got pushed while standing in a line). Even so, the correlation between aggression and testosterone has many remarkable similarities across many vertebrate species that happen to include humans and robins. The same applies to sexual motivation, of course. Anyone who leaves out testosterone in their analysis of human male aggression and sexuality can never hope to understand these phenomena in their true complexity which requires comparisons with other species.

Of course, by saying that hormones play a role in human behavior, including violent crime, one inevitably evokes the old canard that testosterone levels are an excuse for antisocial behavior. The fact is that serious crimes of violence occur at remarkably low rates in modern societies. This means that most young men never engage in any criminal violence, however high their testosterone levels. Still, violent crime is largely perpetrated by young men and high testosterone is a factor in their reckless conduct that we ignore at our peril.

Women have passions as well as men of course. In my next post, I demonstrate that womanly passions are also affected by hormones.

Are Fertile Women More Attractive?

Nigel Barber, Ph.D. — Tue, 07 Jul 2009 13:29:43 +0000

Recent research argues that female sexuality changes in the days surrounding ovulation.
Like other mammals women are now thought to experience sexual heat, or estrus. Earlier sex researchers assumed that women had lost estrus entirely, or had "concealed" it, thereby keeping men in the dark as to when ovulation was actually taking place.

If men had no idea when women were ovulating, (which occurs in mid cycle), then they might be induced to stay around and care for offspring. The idea is that if men had no idea when women were fertile, then attempting to impregnate several women by showing up on those days of the month when each woman is most likely to conceive is a non starter.

The notion that women evolved concealed ovulation as a means of securing investment by men in themselves and their children has had a good inning but researchers have been chipping away at some of the its key assumptions. Is ovulation really hidden, or is it just not advertised? Are men completely in the dark about when women are most fertile in their cycle? Or do they find women more appealing when they are in estrus, just as other male mammals are drawn to estrus females?

Cues to being in heat
A lot of recent research looks for behavioral differences across the menstrual cycle relevant to women's sexual behavior and attractiveness to men. Contrary to the view that human estrus is cryptic, whether unadvertised, or "concealed," many cues can be used to distinguish between women who are close to ovulation and the same individuals at other times in the menstrual cycle.

Feminine lust is probably not one of them. There is no reliable difference in female-initiated sexual behavior between estrus and other parts of the menstrual cycle - as detailed in an earlier post. Some studies reported such a difference but many others did not (1). On the other hand, a great deal of research now indicates that women are more attractive at mid cycle (2).

Their body scent is more attractive to men. Their bodies also become more symmetrical due to changing shape of the soft tissues. Skin becomes paler, which is significant because women are slightly less pigmented than men in all ethnic groups. Even women's voices change, becoming more high-pitched when they are fertile.

As if this were not enough for a species supposedly having concealed ovulation, it turns out that men are also sensitive to when their female partners are ovulating because they are more attentive, and express greater jealousy at these times.

Despite all of the possible cues to their reproductive state, women themselves are not particularly good at detecting whether they are fertile or not, guessing correctly about 60 percent of the time versus a 50 percent chance of being right.

Whether they are aware of it or not, women who are fertile behave differently. In particular, they are more likely to wear revealing clothing and to behave in flirtatious ways (3). The researchers believe that clothing preferences around ovulation may reflect a ratcheting up of female-female competition. Another factor is that they are free of the discomfort of menstruation and pre-menstrual symptoms that may take up as much as a third of the cycle.

All of the above changes in women's attractiveness and flirtatiousness across the menstrual cycle may have a relatively simple hormonal explanation. They might be due to increases in estrogen levels, which peak around the time of ovulation. Other research finds that women whose estrogen (estradiol) level is high are both more physically attractive and more likely to think of cheating on their current mate (4).

Marilyn Monroe is sometimes given as a good example of a high-estrogen woman given both her curvaceousness and physical attractiveness and her proclivity to love them and leave them so far as boyfriends were concerned. She was also competitive with other women and mostly disliked by them. Moreover, she tended to move up the social ladder, dating leading figures right up to the U.S. president. Perhaps ordinary women feel a little bit more like Marilyn Monroe on days of the month when they are fertile.

1. Thornhill, R., & Gangestad, S. W. (2008). The evolutionary biology of human female sexuality. New York: Oxford University Press.
2. Bryant, G. A., & Braselton, M. G. (2009). Vocal cues of ovulation in human females.. Biology Letters, 5, 12-15.
3. Durante, K. M., Norman, P. L., & Haselton, M. G. (2008). Changes in women's choice of dress across the ovulatory cycle: Naturalistic and laboratory-based evidence. Personality and Social Psychology Bulletin, 34, 1451-1460.
4. Durante, K. M., & Norman, P. L. (2009). Oestradiol level and opportunistic mating in women. Biology Letters, 5, 179-182.

A note on chimp mating habits

Not all females form consort relationships. The salient points are (1) that females become more selective in their mating around ovulation and (2) that high-ranking males have a substantial reproductive advantage according to paternity tests. Thanks to commenters.