Progress Daily

 John Coates & Joe Herbert (”Endogenous steroids and financial risk taking on a London trading floor“) took saliva swabs from 17 male traders at a London stock-dealing firm twice a day and measured the samples for testosterone (which is associated with male aggressiveness and sexual behaviour) and cortisol (which is summoned by the body to deal with “fight or flight” emergencies).

When the traders were in profit, their testosterone levels surged. But when they were in loss, or in fluctuation, their cortisol rose sharply.

Testosterone encourages confidence and risk-taking, and has an accumulative effect. Research in animals suggests that, over the long term, high doses of the hormone impair judgement and encourage excessive risks.

Cortisol has a beneficial, euphoric effect in the short term, but after two weeks of exposure to it at high levels, the hormone can erode confidence and magnify fear of risk.

Coates: “If you were to take an identical set of facts and present them to someone high on testosterone and someone who’s got chronic cortisol, the first one would see opportunities everywhere and the second would see nothing but risks.”

“Science unveils hidden drivers of stock bubbles and crashes,” PhysOrg

A study (published in the Public Library of Science) by Soren Krach and Tilo Kircher (”Can Machines Think?“) used functional magnetic-resonance imaging to find out how people’s brains respond to various sorts of robots.

The researchers gave volunteers some laptop computers and asked them to play a “prisoner’s dilemma” game against 4 different opponents: (1) a laptop on its own, (2) a laptop in which the keys were pressed by a pair of robotic hands without a body, (3) a humanoid robot and (4) a human.

The participants were not actually playing an opponent. Instead, they were fed a random series of moves.

A prisoner’s dilemma game involves choosing whether to co-operate with the other player or betray him. Co-operation brings the best outcome, but trying to co-operate when the other player betrays you brings the worst. The game thus requires each player to try to get into the mind of the other, in order to predict what he might do. This sort of thinking tends to increase activity in parts the medial prefrontal cortex and the right temporo-parietal junction. The scanner showed that the more human-like the supposed opponent, the more such neural activity increased. A questionnaire also revealed that the volunteers enjoyed the games most when they played human-like opponents, whom they perceived to be more intelligent.

“I, human,” The Economist Technology Quarterly

A comprehensive RAND National Defense Research Institute study by Seth G. Jones & Martin C. Libicki (”How Terrorist Groups End“) analyzed 648 terrorist groups that existed between 1968 and 2006, drawing from a database maintained by RAND and the Memorial Institute for the Prevention of Terrorism.

The most common way that terrorist groups ended — 43% — was via a transition to the political process. The possibility of a political solution was more likely if (unlike al Qaida) the group had narrow goals.

The second most common way that terrorist groups ended — 40% — was through police and intelligence services either apprehending or killing the key leaders of these groups.

Military force was effective in only 7% of the cases.

Terrorist groups achieved victory in 10% of the cases.

Since 1968, approximately 62% of all terrorist groups have ended, while only 32% of religious terrorist groups have done so. No religious terrorist group has achieved victory since 1968.

Groups of more than 10,000 members were victorious more than 25% of the time, while victory was rare when groups were smaller than 1,000 members. When terrorist groups became involved in an insurgency they ended with a negotiated settlement with the government nearly 50% of the time, achieved victory 25% of the time, and were defeated by military groups 19% of the time.

Terrorist groups from upper-income countries were much more likely to be left-wing or nationalistic, and much less likely to be motivated by religion.

“U.S. Should Rethink ‘War On Terrorism’ Strategy to Deal with Resurgent Al Qaida,” Rand Corporation

Physiognomy, the art or science of predicting inward character from outward form, is undergoing something of a revival. It has recently been found, for example, that women can predict a man’s interest in infant children from his face. Trustworthiness also shows up, as does social dominance.

Now a study by Justin Carré and Cheryl McCormick (”In your face: facial metrics predict aggressive behaviour in the laboratory and in varsity and professional hockey players“) suggests that it is also possible to look a man’s face and read his predisposition to aggression.

Aggressiveness is predictable from the ratio between the width of a person’s face and its height. This ratio differs systematically between men and women (men have wider faces) and that the difference arises during puberty, when sex hormones are reshaping people’s bodies. The cause seems to be exposure to testosterone, which is also known to make people aggressive.

Carré & McCormick obtained photographs of several university and professional Canadian ice-hockey teams, and measured the facial ratios of the players. They also obtained those players’ penalty records. The wider a player’s face, the more time he spent in penalty box.

Carré and McCormick then recruited several dozen university undergratuates of both sexes and got them to play a game against what they thought was a person in another room but was actually a computer. Various measures of aggression taken during this game suggested the same result as with the hockey players. Aggression was not, however, predictable in women students.

“Facing the truth,” The Economist

Helicobacter pylori, a bacterium, is fast vanishing from the rich world.

Martin Blaser has linked the bug’s disappearance with increased levels of obesity, cancer of the esophagus and, as of last month, asthma (see “Does Helicobacter pylori protect against asthma and allergy?.”)

H. pylori’s relatives have probably been living in mammalian stomachs since the mammals began, some 150m years ago. It, itself, has been around for at least 60,000 years and until about 50 years ago it infected 70-80% of the human population. Now, as a consequence of the routine use of antibiotics and improved hygiene, only 5% of American children have it.

H. pylori helps to regulate stomach-acid levels. If the stomach becomes too acid, the bug may produce cag, which lowers the acid level. But cag is toxic to the stomach lining, and can provoke ulcers and cancers.

Antibiotics may be used as an anti-ulcer treatment but this kills H. pylori’s homeostatic effect and allows the strength of the stomach acid to rise chronically, causing gastroesophageal reflux disease (which feels like bad heartburn). Over time, the damage the excess acid does to the walls of the esophagus may cause cancer.

When Blaser analysed the National Health and Nutrition Examination Survey database, he found that US children between the ages of 3 and 13 who are infected with H. pylori are 60% less likely to have asthma than their uninfected contemporaries.

H. pylori also has an effect on two of the hormones that control appetite — ghrelin, which makes you feel hungry, and leptin, which does the opposite. People without H. pylori produce more ghrelin than those with.

“The twists and turns of fate,” The Economist