MATEUS ACIOLIAfter analyzing data on roughly 5,000 people from 94 modern population groups, a team of Ibero-American geneticists and physical anthropologists has gathered enough evidence to contest one of the strangest and most controversial theories to find its way to the pages of major scientific journals in the last five years: the theory that measuring a permanent physical attribute of a man’s skull provides a reliable predictor of his degree of honesty and aggression. According to this contentious thesis, which flirts with the Lombrosian ideas that were defended in the 19th century and thoroughly discredited years ago, the ratio between the width and height of a man’s face is associated with the type of behavior this person displays (although the same reasoning would not hold true for women). Men with proportionately wider faces are purported to be less ethical and more violent.
Natural selection is to blame for this, according to advocates of the theory. During the process of evolution, they claim, female Homo sapiens preferred to mate with males who had broader faces and who had a greater tendency to rely on trickery and force to get what they wanted because they felt they were powerful, feared leaders. Ergo, as time went by – following this line of reasoning – wider skulls became a trademark of more desirable, potent men with greater reproductive success, who would in turn be the most dishonest and ferocious. Can any credence be given to this idea that the measure of meanness is imprinted in the bones of a man’s face – and only a man’s? No, it can’t. Scheduled for publication in the scientific journal PLoS One in the first half of this month, a study by scientists from Brazil, Argentina, Mexico, and Spain says precisely this in a firm but polite tone.
“We found no significant indication that populations or individuals who display a higher degree of bellicosity, aggressive behavior, or power-mediated behavior have wider faces,” says the geneticist Maria Cátira Bortolini of the Federal University of Rio Grande do Sul (UFRGS), one of the study’s coordinators. “Nor did we find any link between this physical characteristic and an alleged reproductive advantage during the evolutionary process.” If broader-faced males had been preferred by females during evolution, these individuals would be expected to have produced more descendants than their weaker rivals (or those who were perceived as weaker), with longer faces. In the analyzed sample, however, the number of offspring produced by men with wider faces did not differ significantly from other men.
Equipe de ArteThe claim that a wider male face represents an adaptive trait that evolved through natural selection – an argument used to underpin the thesis of the neo-Lombrosians – was also not confirmed by the new study. This question has not been entirely settled, although most research affirms that sexual dimorphism is less pronounced in our species than in other primates. In other words, human males and females do not display marked physical differences that were shaped by evolution. Sexual dimorphism is, on the other hand, evident in some plants and animals. The lion, for example, has a showy, intimidating mane, an adornment that the female lion lacks.
Whether or not evolution shaped the width of the male face, there is no solid ground for concluding that this anatomical parameter is in itself a kind of biological measure of a man’s character and aggressive behavior, according to the international research team. “Correlating a single physical attribute with a complex human behavior, like the issue of ethics and aggression, has no scientific validity and is a dangerous idea,” states Argentinean physical anthropologist Rolando González-José, who is with the Patagonian National Research Center in Puerto Madryn and coauthored the PLoS One article. “In addition to not holding up from a scientific point of view, as we have shown in our work, this type of reasoning, which fails to take into account people’s social and cultural context, opens the door to arbitrary, eugenic policies.”
Equipe de ArteThe scientists used their own databases along with some available in other scientific studies to gather information on the head width of a large and diversified sampling of human skulls. The analyzed populations included groups from a vast array of social and cultural contexts and from societies with a reputation for displaying greater or lesser degrees of violence, such as inhabitants of developed and developing countries and of indigenous tribes. The study also used anthropometric data from prisoners incarcerated early last century at the Mexico City Federal Penitentiary – a place where, by definition, the concentration of dishonest, bellicose men must have been high. “We’re not saying that genetics or biology doesn’t influence people’s behavior,” explains Claiton Bau, a specialist in psychiatric genetics at UFRGS, who signed the article along with González-José and Bortolini. “Of course they have an influence, but they do not have a deterministic impact on complex behavior like individual ethics. Their impact is probabilistic. The environment also influences people throughout their lives. In the case of the brain, it’s not the shape that matters but the (cognitive) function played by the region.”
The controversial physical trait said to be associated with male malevolence is calculated based on an index called facial width-to-height ratio (fWHR). Facial width is found by measuring the distance between two points on the skull called the left and right zygions, which lie at the far sides of the head, near the ears. Face height is determined by the distance between two other points, the nasion and prosthion. The nasion is located in the middle of the face between the eyebrows and slightly above the nasal bridge, while the prosthion lies just above the upper lip, likewise in the middle of the face. In men, the broader the face in relation to its height, the greater the fWHR ratio – and, according to the neo-Lombrosians, the greater an individual’s lack of ethics and penchant for aggressive behavior.
The recent article that most explicitly explored this practically racist notion of linking dishonesty to a physical attribute of the skull was a scientific paper printed on July 6, 2012, in the scientific journal Proceedings of the Royal Society B, published by Britain’s well-known and esteemed Royal Society. The title of the study gives a good clue to its contents: “Bad to the bone: facial structure predicts unethical behaviour.” In the article, Michael P. Haselhuhn and Elaine M. Wong, of the University of Wisconsin-Milwaukee (UW-M), report the results of two behavioral experiments, typically used in business schools, which serve as support for their thesis.
In the first test, 192 MBA students (115 men and 77 women), with an average age of 28, took part in a version of the Bullard Houses negotiation exercise. In the test, students were randomly assigned to play the role of a seller or buyer of property, in a simulation meant to measure each negotiator’s ethics. In the variation of the exercise used by Haselhuhn and Wong, the entire transaction took place by email, so that no one knew what the other person looked like.
For the deal to go through, a potential conflict had to be circumvented. The seller would only close the deal if he or she had a guarantee that the property would not be used for commercial purposes, while the buyer would be unwilling to offer any such guarantee (the buyer was not supposed to divulge his or her true plans, which were to build a hotel there). At the end of the experiment, 13 male and 5 female buyers had tricked the seller. In the case of male participants, the deceivers had wider faces than those who did not resort to unethical behavior. No such correlation was found for women. Facial measurements were obtained based on digital photographs of participants.
The second experiment was designed to detect the occurrence of another form of cheating: lying about the results of a virtual dice game in order to increase the player’s chances of receiving a financial reward in a lottery. The authors recruited 103 undergraduates with an average age of 22, of which 49% were male. Participants took a survey to measure how powerful they felt. According to the study’s authors, a correlation was again found between men with wider faces and unethical behavior. Those who reported higher results in the dice game were those who defined themselves as more powerful – precisely the males with wider faces. Similarly, no such correlation was found among the women.
The last paragraph of the article by the two authors from UW-M summarizes the theses they drew from these two experiments: “In conclusion, our research provides a new perspective to the study of the evolutionary foundations of morality by identifying a genetically determined physical predictor of unethical behavior. We demonstrate that men with wider faces (relative to facial height) feel more powerful, and these feelings of power lead directly to less ethical behavior, including lying and cheating. Perhaps some men truly are bad to the bone.”
Contacted by Pesquisa FAPESP in mid-December, Haselhuhn said he did not feel comfortable commenting on the work of his Ibero-American colleagues before having access to the final, published version of the article. “The only statement that I can currently make is that the forthcoming paper really has little to do with our ‘Bad to the bone’ paper except to make the obvious point that unethical behavior and criminal behavior are not necessarily the same thing,” Haselhuhn wrote in an email. “The forthcoming paper more directly disagrees with previous research arguing for sexual dimorphism in fWHR. Although we cite this previous research, exploring the dimorphism is not the focus of our paper.”
Among recent studies, Haselhuhn and Wong’s contains the most forceful affirmations that ethics are associated with the bone width of men’s skulls. But it is not the only one. In an article published online on August 19, 2008, likewise in the Proceedings of the Royal Society B, Justin M. Carré and Cheryl McCormick, both of the Department of Psychology at Brock University in Canada, state that this facial characteristic can serve as a predictor of aggressive behavior. Their scientific evidence: professional and college hockey players with wider faces received more penalty minutes. “Together, these findings suggest that the sexually dimorphic facial width-to-height ratio may be an ‘honest signal’ of propensity for aggressive behaviour,” the authors wrote. In 2009, the same researchers had an article of a much similar tenor accepted by the journal Psychological Science. They reported on experiments in which people associated aggressive behavior with images of men with broader faces. “I can’t imagine anything good coming from this type of study,” Bortolini says.
The desire to associate certain anatomical features of the human skull with the personalities of individuals of our species and also to establish alleged relationships between certain physical parameters and a propensity for dishonesty or the practice of criminal acts is an old one. Written between the late 18th and early 19th centuries, the controversial works of German physician Franz Josef Gall (1758-1828) and his disciple Johann Gaspar Spurzheim (1776-1832) are classic references on the topic. Gall believed that the surface of the skull served as an index of a person’s psychological traits. He divided the brain into 27 regions (others would later slice it into more or fewer sectors). One area was linked to compassion, another to the desire to reproduce, and so on. The size of a region was proportional to the psychological faculty it represented. A bump just above the forehead was a sign of exaggerated benevolence; one around the ears was a predictor of exacerbated aggression. Thus was born cranioscopy, popularized by Spurzheim under the name “phrenology.” To measure the skull was to measure the human psyche.
Although phrenology had fallen into scientific discredit by the mid-19th century – in fact becoming the target of humorous cartoons and paintings, where doctors are portrayed scrutinizing the deformed brains of their patients – this kind of approach has never been without its occasional followers, especially in certain societies. This type of study was widely disseminated in the United States and England. When Italian physician Cesare Lombroso (1835-1909) published Criminal Man in 1876, he produced his own version of the approach, focusing on purportedly typical characteristics of the skulls of hypothetical “born criminals.” According to Lombroso, criminal man has savage features, resembling those of monkeys: a protruding jaw, slanted forehead, big ears, and long arms, among other attributes. Even in the 20th century, racist ideas like Gall’s and Lombroso’s found followers and advocates, such as British scientist Bernard Hollander (1864-1934) and Belgian pedagogue Paul Bouts (1900-1999). “Nazi doctors practiced euthanasia to maintain the so-called purity of the Aryan race,” states Bau, referring to a regime that relied on eugenic ideas influenced in part by phrenology.
In the opinion of González-José, recent studies establishing an alleged correlation between the fWHR ratio and unethical or aggressive behavior are guilty of an extreme and dangerous simplification. “When science tries to explain mechanisms hidden within complex phenomena, careful evaluation is always needed,” says the Argentinean. “A simple statistical association cannot be accepted as proof of a cause and effect relation between the width of a man’s face and unethical behavior.”
GÓMEZ-VALDÉS, J. et al. Lack of support for the association between facial shape and aggression: a reappraisal based on a worldwide population genetics perspective. PLoS One. Forthcoming.