Progress Daily

Correspondent inference theory: people tend to infer the motives of someone who performs an action based on the effects of his actions, and not on external or situational factors.

This makes evolutionary sense. In a world of simple actions and base motivations, it allows a creature to rapidly infer the motivations of another creature. (He’s attacking me because he wants to kill me.)

One place it fails is in our response to terrorism. Because terrorism often results in the horrific deaths of innocents, we mistakenly infer that the horrific deaths of innocents is the primary motivation of the terrorist, and not the means to a different end.

Max Abrahms (”Why Terrorism Does Not Work” — .PDF file here) analyzes the political motivations of 28 terrorist groups: the complete list of “foreign terrorist organizations” designated by the U.S. Department of State since 2001. He lists 42 policy objectives of those groups, and found that they only achieved them 7% of the time.

According to the data, terrorism is more likely to work if 1) the terrorists attack military targets more often than civilian ones, and 2) if they have minimalist goals like evicting a foreign power from their country or winning control of a piece of territory, rather than maximalist objectives like establishing a new political system in the country or annihilating another nation. But even so, terrorism is a pretty ineffective means of influencing policy.

“Countries believe that their civilian populations are attacked not because the terrorist group is protesting unfavorable external conditions such as territorial occupation or poverty. Rather, target countries infer the short-term consequences of terrorism — the deaths of innocent civilians, mass fear, loss of confidence in the government to offer protection, economic contraction, and the inevitable erosion of civil liberties — (are) the objects of the terrorist groups. In short, target countries view the negative consequences of terrorist attacks on their societies and political systems as evidence that the terrorists want them destroyed.”

In other words, terrorism doesn’t work, because it makes people less likely to acquiesce to the terrorists’ demands, no matter how limited they might be: people don’t believe those limited demands are the actual demands.

“The Evolutionary Brain Glitch That Makes Terrorism Fail,” by Bruce Schneier

Alan B Krueger examined 781 terrorist incidents the US state department deemed “significant,” & found that the attackers were from countries with political oppression, not poverty. Some 15 of the 19 hijackers on 11 September 2001 came from wealthy families in a prosperous country - Saudi Arabia. Osama Bin Laden’s background was opulent; Ayman al-Zawahiri is an affluent paediatrician.

The poorest countries, such as Burundi, the Democratic Republic of Congo, Sierra Leone, Eritrea and Liberia, have experienced vicious conflict, but little terrorism.

“Don’t blame the poor,” by Salil Tripathi

Roughly half the world’s people live in makeshift homes in squatter settlements and work in shadow economies. In many countries, more than 80% of all homes and businesses are unregistered; in the Philippines, the figure is 65% and in Tanzania, 90%. More than one-third of the developing world’s GDP is generated in the underground economy, a figure that has increased steadily over the past decade.

In many countries, laws established under colonial rule have never been translated into local languages. Would-be entrepreneurs face a mass of bureaucratic red tape and costly fees. In Egypt, for example, starting a bakery takes 500 days, compliance with 315 laws, visits to 29 agencies and the financial equivalent of 27 times the monthly minimum wage. A recent study by the Inter-American Development Bank in 12 Latin American countries found that only 8% of all enterprises are legally registered and that close to 23 million businesses operate in the shadow economy. The proprietors of these businesses cannot get loans, enforce contracts or expand beyond a personal network of familiar customers and partners.

In San Francisco Solano, a barrio outside Buenos Aires, Argentine economists studied the experience of two communities– one that received title to its land in the early 1980s, another that did not. The group of neighbors that had received legal title to its land surpassed the group without title in a range of social indicators, including quality of house construction, education levels and rates of teen pregnancy.

“Giving the Poor Their Rights,” by Madeleine Albright and Hernando de Soto

Unremitting stress damages the immune system. Two years ago, researchers at UCSF looked at white blood cells from a group of mothers whose children suffered from chronic disorders like autism or cerebral palsy. They found clear signs of accelerated aging in those study subjects who had cared the longest for children with disabilities or who reported the least control over their lives.

The changes took place in microscopic structures called telomeres, which are often compared to the plastic wrappers on the ends of shoelaces and which keep chromosomes from shredding. As a general rule, the youngest cells boast the longest telomeres. But telomeres in the more stressed-out moms were significantly shorter than those of their counterparts, making them, from a genetic point of view, anywhere from nine to 17 years older than their chronological age.

People with low self-esteem are more vulnerable to stress. According to Jens Pruessner, the hippocampus — a finger-size structure located deep in the brain, which helps you form new memories and retrieve old ones — is particularly sensitive to the amount of cortisol flooding your cerebrum. So when cortisol levels begin to rise, the hippocampus sends a set of signals that help shut down the cortisol cascade.

Using several different types of brain scans, Pruessner has shown that people who test below average on self-esteem also tend to have smaller-than-average hippocampi. (The differences become clear only when you compare groups of people.)

Samuel Melamed: “[I]f there is no relief [from stress] and the cortisol stays up for long periods of time, the body stops responding and readjusts the level.”

If you provide mice with an escape route, they typically learn quickly how to avoid a mild electrical shock that occurs a few seconds after they hear a tone. But if the escape route is blocked whenever the tone is sounded, and new shocks occur, the mice will eventually stop trying to run away. Later, even after the escape route is cleared, the animals simply freeze at the sound of the tone– despite the fact that they once knew how to avoid the associated shock.

Animal research has shown that there is a relatively small window for reversing the physiological effects of chronic stress. And once a person’s cortisol level gets completely blunted, it may stay that way for years.

“6 Lessons for Handling Stress,” by Christine Gorman

Wendy Demark-Wahnefried recruited 161 men recently diagnosed with prostate cancer, which they split into 4 groups.

One group ate 3 tablespoons of flaxseed each day (by mixing it with yogurt or water, for example) and maintained a low-fat diet. Of the remaining 3 groups, one maintained a low-fat diet, another ate flaxseed, and the last was a control that made no lifestyle change.

Most of the men had surgery to remove their prostates within 30 days of enrolling in the trial.

Demark-Wahnefried examined the DNA of the removed tumour cells.

The analysis revealed that 50% fewer of the tumour cells from men assigned to eat flaxseed - with or without maintaining a low-fat diet - were actively dividing compared with those of their control counterparts. Maintaining a low-fat diet alone did not appear to affect tumour growth.

Demark-Wahnefried speculates that replacing omega-6 molecules in the body with omega-3 compounds may send chemical signals that tell cells not to divide.

There are about 4 grams of omega-3 fatty acids in 3 tablespoons of flaxseed.

Demark-Wahnefried notes that flaxseed can have a laxative effect.

“Flaxseed may slow prostate tumour growth,” by Roxanne Khamsi

In the ultimatum game, one player divides a pot of money between himself and another. The other then chooses whether to accept the offer. If he rejects it, neither player benefits. A stingy offer (one that is less than about a quarter of the total) is, indeed, usually rejected.

One explanation of the rejectionist strategy is that human psychology is adapted for repeated interactions rather than one-off trades. In this case, taking a tough, if self-sacrificial, line at the beginning pays dividends in future rounds of the game. (When one-off ultimatum games are played by trained economists they do tend to accept stingy offers more often than other people would.) Terence Burnham recently gathered a group of male students of microeconomics and asked them to play the ultimatum game.

Dr Burnham’s research budget ran to a bunch of $40 games. When there are many rounds in the ultimatum game, players learn to split the money more or less equally. He also ran a game of one round only, in which proposers could choose only between offering the other player $25 (ie, more than half the total) or $5. Responders could accept or reject the offer. Dr Burnham took saliva samples from all the students and compared the testosterone levels assessed from those samples with decisions made in the one-round game.

The responders who rejected a low final offer had an average testosterone level more than 50% higher than the average of those who accepted. Five of the 7 men with the highest testosterone levels in the study rejected a $5 ultimate offer but only one of the 19 others made the same decision.

A high testosterone level is correlated with social dominance in many species.

“Money isn’t everything,” The Economist

In every society at all historical times, men’s tendency to commit crimes and other risk-taking behavior rapidly increases in early adolescence, peaks in late adolescence and early adulthood, rapidly decreases throughout the 20s and 30s, and levels off in middle age.

The same age profile characterizes every quantifiable human behavior that is public (i.e., perceived by many potential mates) and costly (i.e., not affordable by all sexual competitors). The relationship between age and productivity among male jazz musicians, male painters, male writers, and male scientists is essentially the same as the age-crime curve. Their productivity quickly peaks in early adulthood, and then equally quickly declines throughout adulthood. The age-genius curve among their female counterparts is much less pronounced; it does not peak or vary as much as a function of age.

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.

“Ten Politically Incorrect Truths About Human Nature,” by Alan S. Miller Ph.D., Satoshi Kanazawa Ph.D.

In a study of East Asians, Europeans and Africans, Jonathan Pritchard found 700 regions of the genome where genes (some of which are active in the brain) appear to have been reshaped by natural selection in recent times.

In East Asians, the average date of these selection events is 6,600 years ago.

The genetic changes occurred around the same time as the beginning of the Neolithic revolution, when societies switched from wild to cultivated foods, such as rice.

“Since it looks like there has been significant evolutionary change over historical time, we’re going to have to rewrite every history book ever written,” said Gregory Cochran. “The distribution of genes influencing relevant psychological traits must have been different in Rome than it is today. The past is not just another country but an entirely different kind of people.” 

John McNeill said that “human nature is not a constant” and that selective pressures have probably been stronger in the last 10,000 years than during any other epoch.

Oxytocin increases a person’s level of trust, at least in psychological experiments, & these levels are known to be under genetic control in other mammals.

In societies where trust pays off, generation after generation, the more trusting individuals should have more progeny and the oxytocin-promoting genes would become more common. If conditions should then change, and the society be engulfed by strife and civil warfare for generations, oxytocin levels might fall as the paranoid produced more progeny.

Napoleon Chagnon for many decades studied the Yanomamo, a warlike people who live in the forests of Brazil and Venezuela. He found that men who had killed in battle had 3 times as many children as those who had not. Since personality is heritable, this would be a mechanism for Yanomamo nature to evolve and become fiercer than usual.

“The Twists and Turns of History, and of DNA,” by Nicholas Wade

According to Paul Collier, 70% of the “bottom billion” (BB) — the world’s poorest 980 million people — live in Africa.

Nearly 3/4 of the people in the BB have recently been through, or are still in the midst of, a civil war. And the poorer a country becomes, the more likely it is to succumb to civil war (”halve the income of the country and you double the risk of civil war”). And once you’ve had one civil war, you’re likely to have more: “Half of all civil wars are postconflict relapses.”

“The Bottom Billion,” by Niall Ferguson

Studies of mice and monkeys show that repeated stress — and a high-fat, high-sugar diet — release a hormone, neuropeptide Y, that causes a buildup of abdominal fat.

Manipulating levels of that hormone could melt fat from areas where it is not desired and accumulate it where it is needed.

Stephen Baker said it could also reduce or eliminate the need for extremely expensive fat replacements used in breast and facial reconstruction and in other surgeries.

Zofia Zukowska divided mice into 4 groups: 2 received a conventional diet, and 2 received a diet high in fat and sugar. Then one group from each diet was forced to stand in cold water for an hour every day, “like the Northern European experience of waiting for a bus with wet feet.”

The remaining groups were exposed to an aggressive alpha male for 10 minutes each day, “like having a bad boss.”

For the mice on the normal diet, “it really didn’t matter whether they were stressed or not. They didn’t have much difference in weight. If anything, the stressed ones weighed less.”

But the stressed mice on the “fast food” diet accumulated twice as much belly fat in the first 2 weeks as those that were not stressed. Over 3 months, they became grossly obese.

Biopsies of the fat showed increased levels of neuropeptide Y, or NPY, a hormone discovered nearly 25 years ago. In the brain, NPY stimulates appetite. In the periphery of the body, it is a growth factor that stimulates enlargement of cells and the production of new blood vessels to supply nourishment.

Zukowska and Lydia Kuo found that the hormone not only enlarged fat cells, but stimulated the production of new fat cells and blood vessels to support them.

A buildup of abdominal fat is a prime contributor to “metabolic syndrome,” which affects 60 million Americans, and sharply increases the risk of diabetes, heart disease and stroke.

The researchers attempted to mimic the process of fat formation by implanting NPY in a slow-release tablet under the skin of mice and monkeys. In each the production of new fat was stimulated around the tablet.

Next, they implanted human fat in nude mice, which have an inhibited immune system and are unable to fight off such transplants. Normally, this fat is reabsorbed by the animal within a couple of weeks. But when they implanted NPY along with it, 99% of the fat was retained after three months.

When the researchers implanted a slow-release tablet of a small molecule that blocks the cellular receptor for NPY, the fat buildup did not occur. Implanting the molecule in a fat deposit caused the fat “to just melt away.”

Within two weeks the fat deposit in the mice had shrunk by half.

The hormone and the receptor are nearly identical in mice, monkeys and humans.

There is a Northern European population that, due to a genetic abnormality, secretes excessive amounts of NPY when stressed. That population is unusually susceptible to obesity and diabetes. In contrast, a Swedish population with a genetic mutation that lessens the receptor’s efficacy is resistant to obesity.

NPY has been injected into humans with no apparent side effects, but its long-term effects have not been studied.

“Stress can be fattening, study finds,” by Thomas H. Maugh II