Psychology Today Blogs - Satoshi Kanazawa

When crime rates go down, recidivism rates go up

Satoshi Kanazawa — Sun, 24 Aug 2008 16:19:53 -0700

What should be the goal of the prison system in society? Should prisons aim to reduce crime rates? Or should they aim to rehabilitate their inmates so that they will not return to prison upon release and instead become productive members of society? As it turns out, we cannot achieve both goals simultaneously.

I was listening to a BBC Radio 4 program one morning, where two so-called “experts” were discussing increasing imprisonment in the UK and its effect on crime rates. One expert was saying that imprisonment and tougher sentences work, because the crime rates have gone down in recent years. The other expert was saying that imprisonment and tougher sentences have not worked, because, while the crime rates have indeed gone down, recidivism (the proportion of released prisoners who commit another crime and go back to prison) has gone up in recent years.

Both experts are mistaken. First, crime rates have gone down since the early 1990s in all the major western nations of the world which have experienced post-World War II baby boom. Crime rates increased in the 1970s in all of these nations as the baby boomers became young adults. As I explain in a previous post, crime is largely a young men’s game (largely, but not entirely, as I explain shortly). Crime rates in most societies at any given time are a very strong function of the proportion of young males in the society; the higher the proportion of young men in the population, the higher the crime rates. It makes perfect sense, because young men are the ones who are committing the crimes.

While politicians and policymakers everywhere, such as Rudolph Giuliani as Mayor of New York City, took inappropriate credit for the falling crime rates during the 1990s, the decreased crime rates had very little (if anything) to do with greater imprisonment rates, tougher law enforcement, or anything the politicians implemented. Crime rates went down in the 1990s simply because the baby boomers “aged out.” They became too old (and, as I explain in another post, too married) to commit crimes. Some criminologists indeed predicted the fall of crime rates in the 1990s before it happened.

Second, recidivism always goes up as a necessary consequence of falling crime rates. As the developmental psychologist Terrie E. Moffitt explains in her classic 1993 article in Psychological Review, there are roughly two types of criminals: adolescence limited and life-course persistent. The adolescence limiteds comprise the vast majority of criminals at any given time, and this is the type of criminals that I discuss in my previous series on criminals. They become increasingly delinquent, violent, and criminal in their late adolescence and early adulthood, then begin to desist from crime in late adulthood into their middle ages, as they get married, settle down, and switch to more conventional ways of life. The life-course persistents, on the other hand, are commonly known as “career criminals.” As the name implies, they do not age out of their criminality, and continue to commit crimes throughout most of their lives. This excellent figure from Moffitt’s 1993 article elucidates her argument.

While many men follow the life trajectories of the adolescence limiteds, the life-course persistents (career criminals) are a genetically distinct type. The late great behavior geneticist Linda Mealey estimated that sociopaths, who are prone to commit crimes because they are incapable of feeling remorse or empathize with others’ pain, comprise about 3-4% of the male population and less than 1% of the female population. The sociopaths nonetheless account for about 20% of the US prison population, and between 33% and 80% of chronic criminal offenders, many of whom are Moffitt’s life-course persistents.

The sociopaths are genetically distinct from the rest of the population, and their prevalence does not vary by social factors, such as the population age structure. As the proportion of adolescence limiteds decreases among the criminals due to the changing population age structure (because there are relatively fewer young men), the proportion of life-course persistents among them must necessarily rise. Since it is the life-course persistents (career criminals) who are most likely to experience recidivism, by returning to prison again and again, there must exist a necessary inverse relationship between crime rates (which are largely set by the number of adolescence limiteds) and the recidivism rates (which are largely set by the number of life-course persistents). So regardless of how tough the law enforcement or how effective the prison system, the lower the crime rates, the higher the recidivism rates in any society at any time. You can have one or the other, but not both at the same time.

One important implication of Moffitt’s groundbreaking work is that all attempts to “rehabilitate” criminals in prisons are doomed to failure. Adolescence limiteds will age out of crime when they are sufficiently old and married anyway, whether they go to prison or not. Life-course persistents will continue to commit crime their entire lives because they are genetically inclined to do so, whether they go to prison or not.

Dropping atomic bombs on Japan was an act of utmost compassion

Satoshi Kanazawa — Thu, 21 Aug 2008 15:37:39 -0700

Just because an act happens to be atrocious does not mean that it is not simultaneously the most humane and compassionate thing to do under the circumstances. Sometimes the alternatives are much worse.

After the fall of Okinawa in June 1945, the Japanese government prepared for the ground invasion by the Allied forces and the final battle on the mainland. Back in August 1944, the government had issued a decree, officially classifying all Japanese citizens (what’s left of them, mostly women, children, and the elderly, as all young men had already been mobilized) as military combatants and armed them all with bamboo spears. Yes, bamboo spears. Here are some contemporary pictures of women and children being armed with bamboo spears and trained to fight the enemies with them.

The women and children were told to fight the invading American ground forces with their bamboo spears till death. They were told that to surrender and be captured by the enemy was the ultimate shame and that they should die fighting instead. The national slogan at the time, propagated by the government and spread to the whole nation, was “Ichioku Gyokusai” (“100 million on a suicidal mission in honor of the Emperor”). They were absolutely prepared to die fighting the American soldiers with their bamboo spears.

Imagine the D-Day invasion in Normandy where the Germans on Omaha Beach were armed only with bamboo spears. It’s not difficult to imagine what the outcome would have been. The opening scenes of Saving Private Ryan would have looked quite different.

By his decision to drop two atomic bombs on Hiroshima and Nagasaki, killing only 200,000 people, Harry S. Truman avoided the annihilation of an entire nation and saved the lives of 100 million people. The Japanese Army had tanks, and the Japanese Navy had airplanes, so they were not impressed with the American tanks and airplanes. Repeated carpet bombings of Tokyo in March 1945 did not faze them. The only thing that would convince the Japanese people, and, more importantly, their military leadership, of the utter American technological superiority and the complete futility of resistance were the atomic bombs, which they did not have.

They would never have surrendered had we not dropped the bombs on Hiroshima and Nagasaki. That would have necessitated ground invasion of mainland Japan by the American forces, which would have led to many, many more Japanese to be killed, up to 100 million. You are equally dead whether you are killed by a bullet or an atomic bomb. 100 million people killed by bullets, one at a time, over weeks and months, is much, much worse, by any account, than 200,000 people killed in a flash of a second by atomic bombs.

All of this is common knowledge for anyone who is even remotely familiar with modern Japanese history.

Not that compassion for enemies at times of war is a good thing or that, even if it was, the Japanese necessarily deserved our compassion, given a large number of atrocities committed by their army. But if it’s compassion you want, you can’t do better than saving the lives of 100 million people.

Remaining puzzle #11: Why does parenthood make us unhappy?

Satoshi Kanazawa — Mon, 18 Aug 2008 10:20:02 -0700

Social surveys often show that parents are less happy than comparable adults without children. This makes no sense from an evolutionary psychological perspective. Happiness (and other emotions) have been evolutionarily selected to induce us to do the right thing in order to attain reproductive success in the context of the ancestral environment. Reproductive success is the be-all and the end-all of all biological existence (including humans). Why then does having children make us unhappy?

I have discovered this to be the case in my own work as well. In my analysis of the U.S. General Social Surveys, I find that marriage and parenthood have a significant positive interaction effect on happiness for both men and women. In nontechnical terms, it means that simultaneously being married and having children make Americans much happier than does the sum of being married and having children. There is an additional boost in happiness if you are both simultaneously. Since reproductive success -- being in a pair-bonded relationship and raising children together -- is the ultimate goal of all humans, this makes perfect sense from an evolutionary psychological perspective.

It made perfect sense, that is, until a reviewer pointed out to me that the main effect of being a parent was very large and negative, slightly larger than the positive interaction effect. In essence, what the totality of my data analysis shows is that being a parent sucks, but it doesn’t suck as much if you are married. Or, conversely, it means that being married is great, but it’s not as great if you also have children. Of course, the question is: Why does being a parent suck? Why does parenthood make us unhappy? This does not make any evolutionary psychological sense at all.

In her recent article “The Joys of Parenthood, Reconsidered,” published in the American Sociological Association’s journal Contexts, the sociologist Robin W. Simon, who has done a lot of research on emotional well-being of parents and nonparents, notes that parents have more frequent negative emotions, and less frequent positive emotions, than nonparents of comparable age. However, she also points out that parents derive “more purpose, more meaning, and greater satisfaction from life” than do nonparents. I wonder if these deeper, philosophical satisfaction with life is meant to encourage humans to reproduce despite more immediate frequent negative emotions and less frequent positive emotions.

The only reason I can think of for why parenthood may make us unhappy is that we are raising our children today in a wholly unnatural environment, in an entirely unnatural manner, relative to our ancestral environment. And our brains, still stuck in the Stone Age, are not designed for us to be parents in the modern world.

Biologically, childhood ends at puberty. After puberty, girls are designed to leave their family and marry into a neighboring tribe, and boys are designed to become self-sufficient and economically independent hunters, in the hope of attracting mates soon. Of course, this is not what happens in the modern family today. We have artificially prolonged childhood called “adolescence” when the children are biologically adults but socially and legally still children. Adolescents past puberty are economically still dependent on their parents, and parents are still expected to raise them. This, incidentally, is at least part of the reason why teenagers rebel against their parents. They are not biologically designed to be economically dependent on their parents and subject to parental control for many years after puberty, at least not nearly to the extent that our laws and social customs require them to be today.

We have to send our children to school, under mandatory education, and the parents sometimes have to support their children through college or, worse yet, graduate school. We cannot use our children for economically productive purposes because there are laws against child labor, so children are net economic burdens. We have to drive them around from ballet lessons to soccer practices. It’s no longer sufficient to make sure that they are well fed and healthy enough to live until sexual maturity so that they can start their own reproductive life at puberty. It is instructive to note in this context that longitudinal research demonstrates that parents were much happier and less stressed in the 1950s when parents (especially mothers) did not have to juggle careers and parenthood than they were in the 1970s.

I am not certain that this is the only reason why parenthood makes us unhappy today. I also wonder whether the “more purpose, more meaning, and greater satisfaction from life” that parents derive than nonparents do means that parents are in fact happier than nonparents despite a whole host of negative emotions they experience more frequently and positive emotions they experience less frequently. At any event, why the very act of reproductive success makes us unhappy, when we are designed to achieve it and everything we do is ultimately geared toward it, remains a mystery for evolutionary psychology (and, once again, only for evolutionary psychology).

Remaining puzzle #10: Why do men murder their pregnant wives/girlfriends?

Satoshi Kanazawa — Thu, 14 Aug 2008 16:36:19 -0700

There have seemingly been a spate of cases where a man has been convicted or suspected of murdering a wife or girlfriend pregnant with his genetic child. The most notorious of these recent cases include Scott Peterson, who was convicted of murdering his pregnant wife and their unborn child and was sentenced to death, and Bobby Cutts, Jr., the former police officer convicted of killing his pregnant girlfriend. Marine Corporal Ceaser Lauren has been accused of murdering and burning the body of his colleague, who once accused him of raping her and was likely carrying his genetic child. Why do these and other men kill pregnant women who are carrying their genetic children?

Murdering a woman who is carrying their genetic child is a mystery from an evolutionary psychological perspective, under any circumstances, because these men always have the option of abandoning them. It is possible that some men, under some circumstances, are not capable of investing in their children or willing to do so for various reasons, but in such cases the most obvious course of action is to abandon them. There is absolutely no reason to murder them. Murder of ingroup members has always been heavily condemned throughout human (and probably protohuman) evolutionary history. It is therefore an extreme act. So why, again, do these men resort to it?

From an evolutionary psychological perspective, the answer could not be that these men were afraid that they would be legally established as the genetic father of the child by a court-ordered DNA test and then legally required to pay child support by the court, with the threat of imprisonment if they do not comply. A DNA test, paternity suit, criminal court, and prisons did not exist in the ancestral environment, so men’s brain cannot truly comprehend them and they are not likely to act out of such concerns.

The human brain has difficulty comprehending and dealing with entities and situations that did not exist in the ancestral environment more than 10,000 years ago. This is known as the Savanna Principle. For example, if men’s brain can truly comprehend artificial means of contraception, such as condoms and the pill, then they should not be upset at all if their wives commit adultery when they are on the pill, because the men would then not be cuckolded by their adulterous wives and duped into raising the resultant child as their own. In reality, however, it makes virtually no difference to the men whether their wives were on the pill or using a condom when they engaged in adultery. It would upset them extremely regardless.

By the same token, if men’s brain can truly comprehend the pill, they should not find the prospect of having sex with a young attractive woman on the pill exciting or arousing at all. In reality, of course, it makes virtually no difference whether the woman is on the pill or not; men find the prospect of having sex with her equally exciting. Nor do they prefer having sex with a less attractive woman not on the pill to having sex with a more attractive woman on the pill. This is because the pill did not exist in the ancestral environment, where more attractive women were always more fertile on average than less attractive women.

Similarly, the reason why men are compelled to kill their pregnant girlfriends and lovers could not be that they are afraid that the birth of the child might jeopardize their marriage, because, once again, they always have the option (exercised by countless men throughout history) of abandoning the lover and her child. Throughout evolutionary history, “married” men have often sired children by other women, and their “wives” usually did not care very much as long as the men did not abandon them and their children. It is only when the men are tempted to leave the wife and her children for the other woman that the women get jealous.

In fact, I cannot think of any reason why men should want to kill women. This is an issue (probably the only issue) over which I disagree with my esteemed colleague, and the Dean of Modern Evolutionary Psychology, David M. Buss, the author, most recently, of the book The Murderer Next Door: Why the Mind is Designed to Kill. I agree with Buss that humans probably have evolved psychological mechanisms that are designed, under some circumstances, to compel them to kill all sorts of other people. But not women, their wives and girlfriends in particular. I can clearly see that men are designed, under some circumstances, to rape women, beat up their wives, or abandon them, but I cannot think of any circumstances in which men should be compelled to kill their wives intentionally.

Female reproductive resources are the most valuable resources in the world. I believe that women -- reproductively capable women who would have your children -- are simply too valuable to kill, and it is therefore a great mystery for evolutionary psychology (and, once again, only for evolutionary psychology) why some men do.

Stump the evolutionary psychologist: Remaining puzzles

Satoshi Kanazawa — Sun, 10 Aug 2008 14:38:01 -0700

Excluding a couple of impromptu posts in response to the current events (the Eliot Spitzer scandal and the breakup of Jimmy Kimmel and Sarah Silverman), I have now posted 50 posts in my blog The Scientific Fundamentalist, and this is my fifty-first. I think it’s time to pause briefly and take stock.

In the last 50 posts, I’ve discussed everything from the penis to God and everything in between. Regardless of the particular topic at hand, the consistent theme in my blog has been to illuminate the power of evolutionary psychology to explain human cognition and behavior -- what we think, how we feel, what we want, and what we do. The range of topics covered in this blog reflects my belief, shared by all evolutionary psychologists, that evolutionary psychology provides the best and the most ultimate (as opposed to the proximate) explanations of human behavior.

The fact that evolutionary psychology can explain so much of human behavior, however, does not mean that it can explain everything. Yet. Although I have absolutely no doubt that evolutionary psychology (along with behavior genetics and cognitive neuroscience) can eventually explain all of human cognitions and behavior some day, the day is still far ahead. There is still so much that we do not know.

However, if I may be Rumsfeldian for a moment, not only do we know what we know, but we also know what we don’t know. There is very little that we don’t know we don’t know, and even less that we don’t know we know. The important point is that, unlike social scientists, we know what we don’t know.

In the last chapter of our book Why Beautiful People Have More Daughters, entitled “Stump the evolutionary psychologists: A few tougher questions” (I owe the chapter title to my magnificent editor, Marian Lizzi, at Perigee; my original, highly imaginative idea for the chapter title was “Conclusion”), we discuss some of these remaining questions in evolutionary psychology, what we still don’t know, the known unknowns. We first revisit the six questions that Robert Wright identified as unresolved puzzles in evolutionary psychology at the end of his 1994 book The Moral Animal.

1. What about homosexuals?

2. Why are siblings often so different from one another?

3. Why do people choose to have few or no kids?

4. Why do people commit suicide?

5. Why do people kill their own children?

6. Why do soldiers die for their countries?

In our book we regard the puzzles 1, 2, and 5 as having been resolved since Wright compiled the list in 1994, but the puzzles 3, 4, and 6 as still largely unresolved. We then add a few new items on the list.

7. Why do children love their parents?

8. Why do parents in advanced industrial nations have so few children?

9. Why do people find a tan attractive? Why do men hog the remote control and typically channel surf much more than women? Why are men mostly responsible for barbecuing and carving meats while women do most of the other cooking?

It is important to remember that these are unresolved questions for evolutionary psychology, nothing else. Some questions, like “Why do children love their parents?”, are not even questions for anybody other than evolutionary psychologists. Of course, children love their parents! It’s natural and makes perfect sense! Yes, it makes perfect sense for everybody, except for the genecentric view of the evolutionary psychologists. In order to maximize their inclusive fitness (reproductive success), parents have to love their children to motivate their parental investment into the children, and, as I discuss in an earlier post, how much parents love and invest in a particular child is determined by the likely future reproductive success of the child -- how physically attractive, intelligent, and sociable the child is -- not by how much the child loves the parents. So it is absolutely unnecessary for children to love their parents, because parents will love them even if they didn’t. It is therefore a mystery why children love their parents.

Since I completed the manuscript for our book a few years ago, I have come up with even more puzzles for evolutionary psychology. I will discuss these in the next few post, and will continue to add to the list as I come up with more unresolved puzzles in the coming months and years.

Men do everything they do in order to get laid VI

Satoshi Kanazawa — Thu, 07 Aug 2008 16:09:13 -0700

A postscript on the media

My paper on the crime-genius connection, which reports the age profile of scientific productivity and the desistance effect of marriage on science, was published in the August 2003 issue of the Journal of Research in Personality. As soon as the issue was published, it was picked up by the media, first by The New Scientist and Nature Science Update, and then it spread like wildfire. Eventually, it was featured in newspapers on every single continent, except for Antarctica.

As often happens in reporting on scientific studies (mine or otherwise), the media got it completely wrong. Here is a sample of the headlines:

A researcher says marriage ruins a beautiful mind (Boston Globe)

Marriage and children kill creativity in men (ABC news online, Australia)

Scientists and crooks, be single (The Telegraph, India)

Feeling sexy makes me a better writer (Independent, UK)

Marriage is not good for science and crime (The Telegraph, UK)

Marriage is bad for creativity (UPI)

If you have been following my posts in this series, you would quickly realize that all of these headlines and articles completely miss the point. My findings don’t mean “marriage is bad for creativity”; in fact, it’s the opposite. They show that creativity is good for marriage. Creative and successful men get married and can stop working, while their less talented counterparts must remain single and continue working in order to attract mates. Similarly, my findings do not mean “marriage is not good for science and crime”; they mean science and crime, if you do them well, are good for marriage in that you can then find a woman who would marry you. And they certainly don’t mean “feeling sexy makes me a better writer”; they mean a better writer feels sexy because he gets laid.

As I explain in my last post, from an evolutionary psychological perspective, marriage and reproductive success are the ultimate goals, and everything men do are the means to the goal. All of the headlines above assume that there is something inherently good about scientific genius or creativity, and marriage and children somehow get in their way. There is absolutely nothing good about scientific genius or creativity except as a means toward reproductive success. Even though they may not be aware of it consciously, men do everything they do in order to get laid, and scientific research is no exception.

Men do everything they do in order to get laid V

Satoshi Kanazawa — Sun, 03 Aug 2008 18:49:00 -0700

Enjoying the fruits of their labor

The social control perspective on the desistance effect of marriage on crime is at best incomplete if marriage has the same desistance effect on scientists. Unlike criminal behavior, scientific activities are completely within conventional society and are thus not at all incompatible with marriage and other strong bonds to conventional society. Unlike criminals, scientists are not subject to social control (by their wives or others), since scientific activities are not illegal or deviant in any way.

I believe an evolutionary psychological theory provides a much simpler and more parsimonious explanation for the desistance effect of marriage for both crime and science, in the form of a single psychological mechanism that predisposes young men to compete and excel early in their adulthood but subsequently turns off after the birth of their children (which quickly followed pair-bonding and regular sex in the absence of reliable means of birth control in the ancestral environment). After their marriage and children, male scientists do not feel like spending hours and hours in their labs, just like married criminals do not feel like taking great risks and committing crimes. But neither scientists nor criminals know why.

From the evolutionary psychological perspective, reproductive success is the end, and everything men do (be it crime or scientific research) is but a means to this ultimate end. From this perspective, the question of why marriage depresses crime and scientific productivity misses the whole point. Does it make sense for men to continue empmloying the means even after they have achieved the ends they were trying to attain with the means? This is why married men are less likely to engage in a whole range of risk-taking behavior, like driving fast, which are designed indirectly and unconsciously to attaract women. Indeed, automobile insurance statistics clearly show that married men have fewer car accidents.

Fluctuating levels of testosterone may provide the biochemical microfoundation for the desistance effect of marriage and parenthood on men, be they criminals or scientists. One longitudinal study shows that men's levels of testosterone go down when they get married, and go up when they get divorced. Another study demonstrates that expectant fathers' testosterone levels fall precipitiously immediately after the birth of their child. If high levels of testosterone predispose men to be more competitive and aggressive, then the sudden drop in testosterone after their marriage and the birth of their child may provide the biochemical reason why men's psychological mechanisms to commit crime and produce scientific work “turn off” when they get married and become fathers.

I will conclude this series with the next post on a few observations on how the media treated this research.

Men do everything they do in order to get laid IV

Satoshi Kanazawa — Thu, 31 Jul 2008 21:14:55 -0700

Why does marriage settle men down?

There is something else that crime and genius have in common. Just as age does, marriage depresses both tendencies.

Criminologists have long known that criminals tend to “settle down” and desist (stop committing crime) once they get married, while unmarried criminals continue their criminal careers. But criminologists tend to explain this phenomenon from the social control perspective pioneered by the criminologist Travis Hirschi (the same Hirschi of the team who first discovered the age-crime curve). Social control theorists argue that marriage creates a bond to the conventional society, and investment in this bond, in the form of a strong marriage, makes it less likely that the criminal would want to remain in the criminal career, which is incompatible with the conventional life. Men must therefore desist from crime when they get married in order to protect their investment in conventional life; in Hirschi’s language, married men develop a “stake in conformity.” Marriage also increases the scope and efficiency of social control on the criminal. Now there is someone living in the same house and monitoring the criminal’s behavior at all times. It would be more difficult for the criminal to escape the wife’s watchful eye and engage in illicit activities.

The social control explanation for the effect of marriage on desistance from crime makes perfect sense, until one realizes that marriage has the same desistance effect on perfectly legal, conventional activities, such as science. A comparison of the “age-genius curve” among scientists who were married at some point in their lives with the same curve among those who never married shows the strong desistance effect of marriage on scientific productivity. Half as many (50.0%) unmarried scientists make their greatest contributions to science in their late 50s as they do in their late 20s. The corresponding percentage among the married scientists is 4.2%. The mean age of peak productivity among the unmarried scientists (39.9) is significantly later than the mean peak age among married scientists (33.9).

Given that the Nobel Prize for scientific achievement didn’t exist in the ancestral environment, the evolved psychological mechanisms of men appear to be rather precisely tuned to marriage as a cue to desistance. Nearly a quarter (23.4%) of all married scientists make their greatest scientific contribution in their career and then desist within five years after their marriage. The mean delay (the difference between their marriage and their peak productivity) is a mere 2.6 years; the median is 3.0 years. It therefore appears that scientists rather quickly desist after marriage, while unmarried scientists continue to do important scientific work. When you remember that great scientific discoveries usually require many years of cumulative and continued research, the near coincidence of the male scientists’ marriages and their desistance (after which they cease to make any greater scientific discoveries) is remarkable. Another study by the sociologists Lowell L. Hargens, James C. McCann, and Barbara F. Reskin also demonstrates that childless research chemists are more productive than their colleagues with children.

You may think that unmarried scientists continue to make scientific contributions much later in their lives because they have more time to devote to their careers. Unmarried and therefore childless scientists do not have to spend time taking care of their children, driving them back and forth between soccer practices and ballet lessons, or doing half the household chores, and that is why unmarried scientists can continue making great contributions to science while married scientists must desist to devote their time to their families. This is precisely Hargens et al.’s interpretation of the negative association between parenthood and productivity among research chemists.

However, I would point out that almost all the scientists in my data on scientific biographies lived in the 18th and 19th centuries, when married men made very little contribution in the domestic sphere and their wives did not have their own careers. Hargens et al.’s data come from 1969-1970, when this was probably still true to a large extent. If anything, married scientists probably had more (rather than less) time to devote to science, because they had someone to take care of their domestic needs at all time.

Why, then, does marriage depress the productivity of all men, criminals and scientists alike? What underlies the desistance effect of marriage? I’ll explain in my next post.

Men do everything they do in order to get laid III

Satoshi Kanazawa — Sun, 27 Jul 2008 16:14:18 -0700

Female choice

The similarity between Bill Gates, Paul McCartney, and the criminals (in fact, all men in evolutionary history) points to a very important concept in evolutionary biology: female choice. In all species in which the female makes greater parental investment than the male (such as humans and all other mammals), mating is a female choice; it happens when the female wants it to happen, and with whom she wants it to happen, not when and with whom the male wants it to happen.

The power of female choice becomes quite apparent in a simple thought experiment. Imagine for a moment a society where sex and mating were entirely a male choice; individuals have sex whenever and with whomever men want, not whenever and with whomever women want. What would happen in such a society? Absolutely nothing, because people would never stop having sex! There would be no civilization in such a society, because people would not do anything besides have sex. This, incidentally, is the reason why gay men never stop having sex: there are no women in their relationships to say no. Sexually active straight men on average have had 16.5 sex partners since age 18; gay men have had 42.8.

In reality, however, women do often say no to men. (In my experience, they always do.) This is why men throughout history have had to conquer foreign lands, win battles and wars, compose symphonies, author books, write sonnets, paint portraits and cathedral ceilings, make scientific discoveries, play in rock bands, and write new computer software, in order to impress women so that they will agree to have sex with them. There would be no civilization, no art, no literature, no music, no Beatles, no Microsoft, if sex and mating were a male choice. Men have built (and destroyed) civilizations in order to impress women so that they might say yes. Women are the reason men do everything.

Once again, my personal hero Bill Maher captures the essence of female choice perfectly, when he quips: “For a man to walk into a bar and have his choice of any woman he wants, he would have to be the ruler of the world. For a woman to have the same power over men, she’d have to do her hair.” In other words, any reasonably attractive young woman exercises as much power as does the (male) ruler of the world.

Put differently, every woman has the power to predict the future, while very few men do. If a man wakes up in the morning and says to himself, “Tonight I will get laid,” the prediction will fail a vast majority of the times, unless he’s incredibly handsome. (Most young men in fact do make this prediction every morning and go to bed alone and disappointed every night.) If a woman -- any woman -- wakes up in the morning and says to herself, “Tonight I will get laid,” the prediction will always come true every time. Such is the power of female choice.

Men do everything they do in order to get laid II

Satoshi Kanazawa — Thu, 24 Jul 2008 18:32:20 -0700

What explains the age profiles of geniuses and criminals?

In a previous post, I explain that, regardless of what they do, whether they be geniuses or criminals, men’s productivity has an identical age profile. It quickly peaks in late adolescence and early adulthood, and then equally quickly declines throughout adulthood. What explains this common age profile?

It turns out that a single evolutionary psychological theory may be able to explain the productivity of both creative geniuses and criminals over the life course. According to this theory, both crime and genius are expressions of young men’s competitive desires, whose ultimate function in the ancestral environment would have been to increase reproductive success.

As I explain in an earlier post, there are reproductive benefits of intense competitiveness to men. In the physical competition for mates, those who are competitive may act violently toward their male rivals. Their violence serves the dual function of protecting their status and honor, and discouraging or altogether eliminating their rivals from future competition. Their competitiveness also inclines them to accumulate resources to attract mates by stealing from others, and the same psychological mechanism can probably induce men who cannot gain legitimate access to women to do so illegitimately through forcible rape. Men who are less inclined toward crime and violence may express their competitiveness through their creative activities in order to attract mates.

There are no reproductive benefits from competition before puberty because prepubescent males are not able to translate their competitive edge into reproductive success. With puberty, however, the benefits of competition rapidly increase. Once the men are reproductively capable, every act of competition (be it through violence, theft, or creative genius) can potentially augment their reproductive success. The benefits of competition stay high after puberty for the remainder of their lives because human males are reproductively capable for most of their adult lives.

This is not the whole story, however. There are also costs associated with competition. Acts of violence can easily result in the man’s own death or injury, and acts of resource appropriation can trigger retaliation from the rightful owners of the resources. A man’s reproductive success is obviously compromised if the competitive acts result in his death or even injury. Before men start reproducing (before their first child), there are few costs of competition. True, being competitive might result in their death or injury, and they might therefore lose in the reproductive game if they are too competitive. However, they also lose by not competing. As I explain in a previous post, if they do not compete for mates in a polygynous society, which all human societies are, they will be left out of the game and end up losing as a result In other words, young men might lose if they are competitive, but given polygyny, they will definitely lose if they are not. So there is little cost of being competitive, even at the risk of death and injury; the alternative -- being a total reproductive loser -- is worse in reproductive terms, which once again is the reason the death penalty cannot deter young men.

The cost of competition, however, rises dramatically with the birth of the first child and subsequent children. True, men still benefit from competition because such acts of competition might attract additional mates even after their initial reproduction. However, a man’s energies and resources are put to better use by protecting and investing in his existing children. In other words, with the birth of children, men should shift their reproductive effort away from mating and toward parenting. If the men die or get injured in their acts of competition, their existing children will suffer; they might starve without their father’s parental investment or fall victim to predation by others without their father’s protection. The costs of competition therefore rapidly increase after the birth of the first child, which usually happens several years after puberty because men need some time to accumulate enough resources and attain sufficient status to attract their first mate. Nevertheless, in the absence of artificial contraception, reproduction probably began at a much earlier age in the ancestral environment than it does today. There is therefore a gap of several years between the rapid rise in the benefits of competition and the similarly rapid rise in its costs.

Both the age-crime curve and the age-genius curve can be explained as the mathematical difference between the benefits and costs of competition. Young men rapidly become more violent, more criminal, and creatively more expressive in late adolescence and early adulthood as the benefits of competition rise, but then their productivity just as rapidly declines in late adulthood as the costs of competition rise and cancel its benefits. Criminality, genius, and productivity in virtually everything else men do vary as they do over the life course because they represent the difference between the benefits and costs of competition.

These calculations have been performed by natural and sexual selection, so to speak, which then equips male brains with a psychological mechanism to incline them to be increasingly competitive immediately after puberty and to make them less competitive right after the birth of the first child. Men themselves do not necessarily make these calculations consciously. They simply do not feel like acting violently, stealing, or conducting additional scientific experiments, or they just want to settle down after the birth of the child, but they do not know why. The intriguing suggestion here is that a single psychological mechanism may be responsible for much of what men do, whether they are criminals or scientists.

Now, given that human society has always been mildly polygynous, there were always many men who did not succeed at securing mates and reproducing. These men had everything to gain and nothing to lose by remaining competitive and violent for their entire lives. However, we are not descended from these men.

By definition, we are all descended from men (and women) who attained some reproductive success. None of us are descended from total reproductive losers who left no offspring. And we are disproportionately descended from those who attained great reproductive success. Twelve children carry the genes of a man who had twelve children, but only one child carries the genes of a man who had only one child. And, of course, no children carry the genes of a man who had no children. (Yes, childlessness is perfectly heritable!) Contemporary men did not inherit from reproductive losers psychological mechanisms that force them to stay competitive and keep trying to secure mates for their entire lives. We all act as if we have children by the time we reach early adulthood, whether we do or not, because we are descended, and inherited our psychological mechanisms, from our ancestors who did.