Thursday, December 31, 2009

Review of 2009

Before I make my predictions for 2010, let me review the ones I made for 2009:

The Neanderthal genome will be fully sequenced. There will be no evidence of interbreeding with modern humans (although proponents of the multiregional model will remain unconvinced). By comparing this genome with ours, we may reconstruct the genome of archaic humans who lived almost a million years ago and who were ancestral to Neanderthals and modern humans.

The Neanderthal genome was not fully sequenced this year. Because much of the reconstructed DNA turned out to be contamination from modern humans, the researchers had to start over. So far, there is no sign of Neanderthal admixture in the modern European genome, including the European variant of the microcephalin gene (which some had thought to have been of Neanderthal origin).

Meanwhile, work will begin on sequencing the genome of early modern humans (10,000 – 40,000 years ago). This project should ultimately prove to be more interesting by showing us how much modern humans have evolved during their relatively short existence. We will probably find out that John Hawks erred on the low side in concluding that natural selection had changed 7% of the human genome over the past 40,000 years.

The work has begun, at least for European populations, but it’s raising more questions than answers. The big question is the fate of the hunter-gatherers who inhabited Upper Paleolithic and Mesolithic Europe. Were they ancestral to present-day Europeans? Or were they replaced by a farming population from the Middle East? To date, the data indicate little genetic continuity between late hunter-gatherers and early farmers. On the other hand, the same data show little continuity between early farmers and present-day Europeans.

Perhaps founder effects are muddling the picture. Whenever some hunter-gatherers adopted agriculture, they and their descendants probably expanded considerably at the expense of neighboring groups. Early farmers would thus come from a very unrepresentative sample of late hunter-gatherers. The transition may have been just as bumpy between early farmers and later populations. Thus, the lack of genetic continuity could be more apparent than real.

In any case, paleo-geneticists should be looking not only at junk DNA but also at genes that have real-world effects. When did ancestral Europeans come to look the way they do now? Was it a gradual process that began when modern humans arrived in Europe some 35,000 years ago? Or did it happen rapidly?

We should also examine genes that regulate growth of brain tissue (like the aforementioned microcephalin variant). How intelligent were Europeans 30,000 years ago, 15,000 years ago, 5,000 years ago?

With the 150th anniversary of The Origin of Species, much will appear in 2009 about Charles Darwin and his life. We already know how he came up with his theory of evolution (Darwin salted away almost everything he wrote), although a few questions remain unanswered. What would he have done if he had lived longer? What did he have in mind for future projects?

Nothing really new has turned up. In 2009, historians questioned the view that Darwin deliberately held back his theory for two decades out of fear of a religious backlash. In fact, he was more afraid of not being taken seriously. He wished to build up his academic reputation before tackling the issue of evolution:

To use the modern jargon, he had to have the papers on the table to prove his worth. … Evolutionary ideas had emerged sensationally in the anonymously published Vestiges of the Natural History of Creation (1844), which could be pooh-poohed by the orthodox scientists of the day as a mishmash of half-baked ideas from the pen of a pseudo-scientist (it was subsequently revealed as the work of the antiquarian and publisher Robert Chambers). Darwin would not want to be taken lightly or dismissed as a mountebank: he was evidently a realist when it came to his career. (Fortey, 2009)

The Second Great Depression will not begin in 2009. In any case, what scares me is not the prospect of a sudden drop in the standard of living. Rather, it’s that of a gradual decline to almost half its current value. That scenario is scarier and likelier. And it’s probably already started. For the past fifteen years, median wages have stagnated despite decent economic growth. What will happen when growth stays in the 0-2% range?

The current recession is drawing to a close, but this should be no cause for self-congratulation. The coming decade will likely bring us stagflation, i.e., declining incomes and rising prices, especially for the basics of life (food, housing, oil, and most other commodities).

The cause? Globalization. The playing field is being leveled, and we’re competing more and more with the rest of the world for the basics of life. With free circulation of capital, goods, and labor—and that seems to be where our elites wish to go—incomes everywhere will tend to gravitate to the same level. There will still be income disparity within each country, perhaps even more (as in Latin America), but the average income level will be similar around the world, except for those countries that opt out of the globalist project.

Things might not be so bad for us if the world’s resources could be increased indefinitely. Our incomes could then stagnate while everyone else catches up (unlikely, though, since much of the world lacks the necessary social capital and political stability). In any case, even that scenario seems unrealistic. Demand is starting to outstrip supply for a number of key commodities, and not just oil. This is what the Club of Rome predicted back in 1972 in its report The Limits to Growth. Unfortunately, this pessimism seemed to be proven wrong when commodity prices fell into a long-term slump after the 1982 recession.

I suspect that warnings about peak oil are going unheeded now because similar warnings were made over thirty years ago. Just more of the same doom and gloom. Or so many think.


Endersby, J. (2009). Creative designs? How Darwin's Origin caused the Victorian crisis of faith, and other myths, TLS 7.3.16.

Fortey, R.A. (2009). How Darwin evolved, TLS 6.1.1.

Wednesday, December 16, 2009

The Montreal massacre. Part II

In debating the causes of the Montreal Massacre, we must confront the psychological similarities between Marc Lépine and his father. Both seem to have had low thresholds for ideation and expression of violence. Was this quick temper passed down from father to son? Or are the similarities only fortuitous?

If these psychological characteristics had passed down from father to son, they could have done so in only one of two ways. The preferred explanation is some kind of role-model conditioning, i.e., Marc Lépine looked to his father as a model for future behavior. But this seems unlikely. Marc hated his father. He repeatedly said so and reproached his mother for not doing enough to protect him from his father’s rage. Nor did he try to renew contact with his father after his parents broke up.

We’re thus left with some kind of unconscious conditioning that occurred before the age of 7 (when his parents broke up) and then began to express itself after puberty. But this too seems unlikely. For one thing, it implies a kind of infancy determinism that is no longer widely accepted in child psychology (Harris, 1998; Kagan, 1996; Kagan, 1998). As Jerome Kagan (1996) points out:

If orphans who spent their first years in a Nazi concentration camp can become productive adults (Moskovitz, 1983) and if young children made homeless by war can learn adaptive strategies after being adopted by nurturing families (Rathbun, DeVirgilio, & Waldfogel, 1958; Winick, Meyer, & Harris, 1975), then one can question the belief that the majority of insecurely attached l-year-olds are at high risk for later psychological problems. Even the behavioral differences among animals in laboratory settings are not very stable from infancy to reproductive maturity: "The findings offer meager support for the idea that significant features of social interactions at maturity are fixed by experiences in early development" (Cairns & Hood, 1983, p. 353). This conclusion affirms a discovery, now more than 20 years old, that even the stereotyped, bizarre social behaviors of 6-month-old isolated macaques can be altered by placing them with younger female monkeys over a 26-week period (Suomi & Harlow, 1972). These facts are also in accord with data on humans. Werner and Smith (1982), who followed a large sample of children from infancy to early childhood, concluded, "As we watched these children grow from babyhood to adulthood, we could not help but respect the self-righting tendencies within them that produced normal development under all but the most persistently
adverse circumstances" (p. 159).

For another thing, children behaviorally resemble their parents even if removed from parental influence shortly after birth. When adopted children are compared with their biological parents, we see moderate to high heritability in transmission of male aggressiveness (Baker et al., 2007; Barker et al., 2009; Rhee and Waldman, 2002). Furthermore, the non-genetic factors seem largely unrelated to parental influence, being either peer pressure outside the home or developmental accidents before and after birth (Harris, 1998).

Thus, to explain the psychological similarities between Marc Lépine and his father, the likeliest cause is genetic transmission. Either that or the similarities are just fortuitous.

The latter possibility should not be ruled out. When Monique Lépine sued for divorce, Rachid Gharbi strenuously denied her claims that he had abused their son. So perhaps we’re hearing just one side of the story. Remember, these proceedings happened before the liberalization of Canada’s divorce laws. Monique had to provide evidence of abuse to get her divorce.

To find out Rachid Gharbi’s side of the story, I turned to an article by an Algerian author on the “Impact of parental upbringing on child development.” The author’s first point is that Algerian upbringing is sex-specific. In boys, violent behavior is accepted and even encouraged:

In Algerian society for example, children are raised according to their sex. A boy usually receives an authoritarian and severe type of upbringing that will prepare him to become aware of the responsibilities that await him in adulthood, notably responsibility for his family and for the elderly. This is why a mother will allow her son to fight in the street and will scarcely be alarmed if the boy has a fall or if she sees a bruise. The boy of an Algerian family is accustomed from an early age to being hit hard without whimpering too much. People orient him more toward combat sports and group games in order to arm him with courage and endurance—virtues deemed to be manly. (Assous, 2005)

The purpose of this upbringing is not to suppress male aggressiveness but rather to channel it in the right direction: loyalty to the family and to tradition:

It is true that, in Arab and Muslim culture, parents are encouraged to discipline a child and to teach him obedience and submission by first using methods of communication and patience, but in the case of rebellion and especially of non-respect of Islamic laws it is recommended to use corporal punishment (e.g., a child who does not practice prayer is reprimanded as early as 10 years of age). (Assous, 2005)

Parental control is especially problematic after puberty:

Thus, during adolescence for example, the child will become more and more difficult to control. This behavioral disorder evidently pushes the parents to display more ill treatment in their authority and the schoolteachers to be more severe. (Assous, 2005)

The author presents an analysis of this corporal punishment, on the basis of cases brought to the notice of hospital authorities:

- it is directed much more at boys than at girls, by a ratio of almost 3 to 1

- it is inflicted (in order of importance) by schoolteachers, parents, neighbors, and other relatives

- it usually involves the use of blunt, non-cutting objects: a belt, a pipe, or a wire

- it is directed (in order of importance) at the head, arms or legs, belly, and chest

- the injuries (in order of importance) are multiple fractures, bruises, burns, scratches, and bites

The author goes on to note:

In Algerian society, even today, the absolute authority of parents over their children is seldom called into question by adults if it is exercised judiciously and without apparent adverse effects, and even though it often happens that more or less serious incidents cannot be avoided by parents in the grip of an intense anger that they cannot manage to control. (Assous, 2005)

Clearly, Rachid Gharbi and Monique Lépine had different notions of how young boys should be brought up. Monique came from a cultural background where corporal punishment is a last resort and usually takes the form of spanking. The preferred form of punishment is shaming: the boy is made to realize that he has done something wrong. At that point, his sense of shame will do the rest. If the boy has no sense of shame, he is considered to be abnormal, if not mentally ill.

In contrast, Algerian parents use shaming mainly to control girls. For boys, it seems to be at best a secondary or even tertiary means of control, the main ones being the threat and use of corporal punishment.

Why is child discipline so different in Algeria? The reason seems to be that violence is much more omnipresent. The average Algerian male is more ready and willing to use violence preemptively or in self-defense. Social peace is maintained largely by an implicit balance of terror: violence is deterred by the threat of retaliation—if not by the victim, then by a male relative. Evidently, the balance cannot always be maintained...

This aspect of Algerian life is described by Frantz Fanon in Les damnés de la terre:

It’s a fact, the magistrates will tell you, that four fifths of the cases heard involve assault and battery. The crime rate in Algeria is one of the highest in the world, they claim. There are no petty delinquents. When the Algerian, and this applies to all North Africans, puts himself on the wrong side of the law, he always goes to extremes (Fanon, 2004, p. 222)

The act of violence itself shows less restraint and the precipitating causes seem banal:

Autopsies undeniably establish this fact: the killer gives the impression he wanted to kill an incalculable number of times given the equal deadliness of the wounds inflicted.

… Very often the magistrates and police officers are stunned by the motives for the murder: a gesture, an allusion, an ambiguous remark, a quarrel over the ownership of an olive tree or an animal that has strayed a few feet. The search for the cause, which is expected to justify and pin down the murder, in some cases a double or triple murder, turns up a hopelessly trivial motive. Hence the frequent impression that the community is hiding the real motives.
(Fanon, 2004, p. 222)

The reason for this state of affairs ultimately goes back to the recentness of central authority in Algeria. Before the French conquest in the 19th century, each family depended on its male members to defend its interests. There were law courts, but they had no power to enforce their rulings. It was up to the aggrieved party to do the enforcement.

This situation was not unique. In fact, it was typical of all human societies and remains so in many parts of the world today. It changed only with the rise of central authority and its monopoly on the use of violence. With this change, the State put an end to the worst sort of tyranny: the daily fear of being assaulted or even killed, not by a foreign invader but by someone in your own town or village. The violent male went from hero to zero.

Initially, people complied with the new order by changing their behavior within the limits of phenotypic plasticity. The result was a more peaceful society where violent males were less often imitated, celebrated, and accommodated. This shift in the mean phenotype then contributed to a slower but similar shift in the mean genotype, by creating an environment that favored the reproduction of certain individuals at the expense of others. There was thus Baldwinian selection for individuals less predisposed to violence and more predisposed to submissiveness.

This process is described by the historical economist Gregory Clark with respect to England. Once central authority had become established, male homicide fell steadily from the twelfth century to the early nineteenth. Meanwhile, there was a parallel decline in blood sports and other forms of exhibitionist violence (cock fighting, bear and bull baiting, public executions) that nonetheless remained legal throughout this period. Clark ascribes this behavioral change to the reproductive success of upper- and middle-class individuals who differed statistically in their predispositions from the much larger lower class, including predispositions to violence. Although initially a small minority in medieval England, such individuals grew in number and their descendants gradually replaced the lower class through downward mobility. By the nineteenth century, their lineages accounted for most of the English population (Clark, 2007, pp. 124-129, 182-183; Clark, 2009).


Assous, A. (2005). L’impact de l’éducation parentale sur le développement de l’enfant, Hawwa, 3(3), 354-369.

Baker, L.A., K.C. Jacobson, A. Raine, D.I. Lozano, and S. Bezdjian. (2007). Genetic and environmental bases of childhood antisocial behavior: a multi-informant twin study, Journal of Abnormal Psychology, 116, 219-235.

Barker, E.D., H. Larson, E. Viding, B. Maughan, F. Rijsdijk, N. Fontaine, and R. Plomin. (2009). Common genetic but specific environmental influences for aggressive and deceitful behaviors in preadolescent males, Journal of Psychopathology and Behavioral Assessment, 31, 299-308.

Clark, G. (2009). The indicted and the wealthy: surnames, reproductive success, genetic selection and social class in pre-industrial England,

Clark, G. (2007). A Farewell to Alms. A Brief Economic History of the World, Princeton University Press, Princeton and Oxford.

Fanon, F. (2004). The Wretched of the Earth, New York: Grove Press.

Harris, J. R. (1998). The nurture assumption: Why children turn out the way they do, Free Press.

Kagan, J. (1998). Three Seductive Ideas, Cambridge, Harvard University Press.

Kagan, J. (1996). Three pleasing ideas, American Psychologist, 51, 901-908.

Rhee, S.H., and I.D. Waldman. (2002). Genetic and environmental influences on antisocial behavior: A meta-analysis of twin and adoption studies, Psychological Bulletin, 128, 490-529.

Thursday, December 10, 2009

The Montreal massacre ... 20 years later

On December 6, 1989, a 25-year-old man walked into Montreal’s École polytechnique and murdered fourteen women. The event is still being debated … twenty years later.

We know the immediate cause. The murderer, Marc Lépine, felt that places like the École polytechnique were training women to take jobs that had been mainly held by men like himself. In April 1989 he had met with a university admissions officer and complained about how women were taking over the job market. Earlier still, he had spoken out to men about his dislike of feminists, career women, and women in traditionally male occupations such as the police, saying that women should remain at home and care for their families. This resentment may have been exacerbated by his inability to find a girlfriend. He was generally ill at ease around women, tending to boss them around and showing off his knowledge in front of them

For many people, the debate stops there. Marc Lépine resented women, especially ‘feminists’, and this resentment led to the Montreal massacre. For others, such resentment does not in itself explain what happened. Lépine’s personal history points to a longstanding tendency toward asociality, short-temperedness, and ideation of violent behavior, particularly after he reached puberty in the late 1970s:

Late 1970s – When his sister made fun of him for not having a girlfriend, he fantasized about her death and made a mock grave for her.

September 1981 – He applied to join the Canadian Armed Forces as an officer cadet but was rejected during the interview process because he seemed antisocial and unable to accept authority.

1982-84 – At junior college, colleagues saw him as being nervous, hyperactive, and immature.

1987 – He lost his job at a hospital because of aggressive behavior, disrespect of superiors, and carelessness in his work. He was enraged at his dismissal, and at the time described a plan to go on a murderous rampage and then commit suicide. His friends said he was unpredictable and would fly into rages when frustrated.

Some people trace this behavioral pattern to his early childhood, specifically as the son of a Catholic French-Canadian mother, Monique Lépine, and a Muslim Algerian father, Rachid Liass Gharbi. The latter’s psychological profile looks very similar to Marc Lépine’s:

Gharbi was an authoritarian, possessive and jealous man, frequently violent towards his wife and his children. Gharbi had contempt for women and believed that they were only intended to serve men. He required his wife to act as his personal secretary, slapping her if she made any errors in typing, and forcing her retype documents in spite of the cries of their toddler. He was also neglectful and abusive towards his children, particularly his son, and discouraged any tenderness, as he considered it spoiling. In 1970, following an incident in which Gharbi struck his son so hard that the marks on his face were visible a week later, his mother decided to leave. (Marc Lépine - Wikipedia)

His mother had divorced his father over the issue of abuse, which had extended to the children. Beaten by his father, Rachid Liass Gharbi, for such minor problems as singing too loudly or failing to greet him in the morning, Lépine had learned to fear him.

"He was a brutal man," Monique Lépine told the court, "who did not seem to have any control over his emotions... It was always a physical gesture, a violent gesture, and always right in the face." Monique's sister confirmed these details to the judge, although Gharbi protested that they were not true. Nevertheless, the judge awarded custody to Monique. Still, young Gamil was not free of the man until he was 7 years old, and the exposure for that long to Gharbi's temper and beliefs had a strong influence. The boy so hated him that when he was 13, he changed his name to Marc Lépine.
(Ramsland, 2004)

The hypothesis here is that Gharbi exerted a profound influence on his son’s future psychological development. Some rightwing bloggers go so far as to suggest that Marc Lépine himself became a Muslim, as evidenced by the beard he grew as a young man. This is unlikely for several reasons:

– He was baptized a Roman Catholic and received no religious instruction. His mother describes him as "a confirmed atheist all his life."

– He had no contact with his father past the age of 7.

– At the age of 14, he legally changed his name from Gamil Rodrigue Liass Gharbi to Marc Lépine. This was motivated partly by hatred of his father and partly by a desire to avoid being treated as an Arab at school.

– His suicide note contains no Islamic references. In fact, his use of several Latin expressions (Ad Patres, Casus Belli, Alea Jacta Est) suggests he still felt some connection with Roman Catholicism.

– As for his beard, he grew it to cover up his acne.

O.K., so Marc Lépine was not a crypto-Muslim. But maybe he unconsciously imitated his father’s behavior. We often hear this kind of argument at trials where a violent offender is shown to have had an equally violent father. The offender should thus be judged more leniently, given his poor role-model.

In Marc Lépine’s case, this kind of argument is at the limit of credibility. Remember, Gharbi was a hated parental figure who had left Lépine’s life at the age of 7. More to the point, we see the same psychological similarity between parents and their children even when the children are taken away shortly after birth and put up for adoption:

… compared to genetic children, American adoptees have a higher overall risk of contact with mental health professionals, specifically for eating disorders, learning disabilities, personality disorders and attention deficit hyperactivity disorder … They also have lower achievement and more problems in school, abuse drugs and alcohol more, and fight with or lie to parents more than genetic children …

… Adoptees may be genetically predisposed to negative outcomes at higher rates than the general population. Genetic factors clearly contribute to alcohol and drug addiction, as well as to some mental disorders like attention deficit hyperactivity disorder and schizophrenia …. An association between nonviolent criminality has been found between European adoptees and their genetic parents … Furthermore, research with Swedish adoptees suggests 55-60% of their educational performance is explained by genetic factors, and that the number of years of school adoptees complete is significantly related to how many years their genetic mothers completed
(Gibson, 2009).

On the specific issue of male aggressiveness, we see moderate to high heritability when adopted children are compared with their biological parents. A heritability of 40% is suggested by a meta-analysis of 51 twin and adoption studies (Rhee & Waldman, 2002). A later twin study indicates a heritability of 96%, the subjects being 9-10 year-olds from diverse ethnic backgrounds (Baker et al., 2007). This higher figure is due to the closer ages of the subjects and the use of a panel of evaluators to rate each of them. According to the latest twin study, heritability is 40% when the twins have different evaluators and 69% when they have the same evaluator (Barker et al., 2009).

This is not to say that the Montreal massacre was genetically inevitable. If Lépine had found a girlfriend, who would have put up with him, he would have probably become a man like his father but nothing more serious. The tragedy on December 6, 1989 resulted from three interacting factors: 1) a latent predisposition to violence, probably in the form of low thresholds for ideation and expression of violent behavior; 2) lack of close friends, especially female friends; and 3) an enabling ideology.


Baker, L.A., K.C. Jacobson, A. Raine, D.I. Lozano, and S. Bezdjian. (2007). Genetic and environmental bases of childhood antisocial behavior: a multi-informant twin study, Journal of Abnormal Psychology, 116, 219-235.

Barker, E.D., H. Larson, E. Viding, B. Maughan, F. Rijsdijk, N. Fontaine, and R. Plomin. (2009). Common genetic but specific environmental influences for aggressive and deceitful behaviors in preadolescent males, Journal of Psychopathology and Behavioral Assessment, early view.

Gibson, K. (2009). Differential parental investment in families with both adopted and genetic children, Evolution and Human Behavior, 30, 184-189.

Lépine, Monique & H. Gagné. (2008). Aftermath, Viking.

Lépine, Marc. (1989). Lettre de Marc Lépine,

Marc Lépine - Wikipedia

Ramsland, K. (2004), Gendercide – The Montreal Massacre.

Report of Coroner’s Investigation

Rhee, S.H., and I.D. Waldman. (2002). Genetic and environmental influences on antisocial behavior: A meta-analysis of twin and adoption studies, Psychological Bulletin, 128, 490-529.

Thursday, December 3, 2009

Recent evolution of complex behavior

I once knew an African student who told me that his language had no words for “good” or “evil”. When the missionaries translated their materials into his language, they had to write “Jesus is beautiful” instead of “Jesus is good.”

This sort of semantic evolution has occurred in all human languages. People have expressed new concepts by recycling older ones. Typically, these older concepts refer to primary sensations that are largely hardwired, i.e., ‘beautiful’, ‘cold’, ‘hot’, and so on.

Interestingly, it looks as if some of this hardwiring is being reused when we imagine evolutionarily recent concepts. For instance, when we recognize someone as friendly, we use neural pathways that are associated with the recognition of warmth.

During the autumn of 2006, a series of volunteers arrived at Yale University's psychology building. Each was greeted in the lobby by a researcher, who accompanied them up to the fourth floor. In the elevator, the researcher casually asked the volunteer to hold the drink she was carrying while she noted down their name. The subjects did not know it, but the experiment began the moment they took the cup.Once in the lab, the 40 or so volunteers read a description of a fictitious person and then answered questions about the character. Those who had held an iced coffee, rather than a hot one, rated the imaginary figure as less warm and friendly, even though eachvolunteer had read the same description. Answers to other questions about the figure, such as whether the character appeared honest, were unaffected by the type of drink. (Williams & Bargh, 2008).

Similarly, we have developed the ability to form moral judgments by building upon a mental algorithm that serves to judge cleanliness:

In one recent study, Simone Schnall at the University of Plymouth, UK, and colleagues showed half their volunteers a neutral film and the other half the toilet scene from the film Trainspotting. (The uninitiated need only use their imagination here: the clip features what is described as the "worst toilet in Scotland".) Those who viewed the Trainspotting clip subsequently made more severe judgements about unethical acts such as cannibalism than volunteers who had viewed the neutral scene. Exposing subjects to a fart smell and placing them in a filthy room had a similar effect (Schnall et al., 2008).

Chen-Bo Zhong of the University of Toronto in Canada and Katie Liljenquist, now at Brigham Young University in Provo, Utah, asked volunteers to read a first-person account of either an ethical act or an act of sabotage. They then had to rate the desirability of various household objects, including soap, toothpaste, CD cases and chocolate bars. Those who had read the sabotage story showed a greater preference for the cleaning products than those who had not.

A self-perception of physical cleanliness thus seems linked to one of moral cleanliness. Moreover, like Pontius Pilate, the mere act of washing your hands reduces feelings of moral responsibility.

… In another part of their study, Zhong's team asked volunteers to recall an unethical deed from their past. Under the guise of a health and safety precaution, he then gave half the subjects antiseptic wipes to clean their hands. The participants were then asked if they would take part in another experiment, this time to help out a desperate graduate student. Only 40 per cent of the subjects who had cleaned their hands volunteered, compared with almost three-quarters of those who hadn't. (Zhong & Liljenquist, 2006)

These studies suggest an answer to a question that has bothered me. How is that complex and relatively recent social behaviors often have moderate to high heritabilities? Surely such hardwiring would have taken an impossibly long time to evolve? Just think of all the genes involved…

Well, the answer is surprisingly simple. Natural selection has simply altered a hardwired algorithm that already exists. There’s no need to build it all from scratch. You just jerry-rig what you already have.


Mangan’s Miscellany is back!! In fact, he's back at his old address ( and at a new one (


Giles, J. (2009). Icy stares and dirty minds: Hitch-hiking emotions, New Scientist 2725:* 15 September 2009

Schnall, S., J. Haidt, G.L. Clore, A.H. Jordan. (2008).
Disgust as embodied moral judgment, Personality and Social Psychology Bulletin, 34, 1096-1109.

Williams, L.E. & J.A. Bargh. (2008).
Experiencing physical warmth promotes interpersonal warmth, Science, 322, 606-607

Zhong, C.B. & K. Liljenquist, K. (2006). Washing away your sins: Threatened moralityand physical cleansing, Science, 313, 1451-1452.