Progress Daily

The number of foreign residents in Germany increased from 3m in 1971 to 7.5m in 2000 though the number of foreigners in the workforce did not budge. Today immigrants account for about 10% of the population of most west European countries, and up to 30% in some of Europe’s great cities.

In the middle of the 20th century there were almost no Muslims in Europe. Today there are 15m-17m, making up about half of all new arrivals in Europe.

Only 19% of Europeans think immigration to be a good thing for their country; 57% think that their country has “too many foreigners.”

Review of Christopher Caldwell’s Reflections on the Revolution in Europe: Immigration, Islam and the West

In a study just published in Evolution and Human Behavior (”Costs and benefits of fat-free muscle mass in men: relationship to mating success, dietary requirements, and native immunity“), Steven Gaulin analyzes muscularity.

The data came from the NHNES, which followed 12,000 American men and women over the course of 6 years. The researchers found that men require 50% more calories than women do, even after adjusting for activity levels, and that their muscle mass is the strongest predictor of their intake of calories — stronger than their occupation or their body-mass index. Men’s immune systems are less effective than those of women (which was known before), and become worse the more muscular the men are (which was not).

The more muscular a man, the more sexual partners he reported, both in the past year and over his lifetime, and the earlier his first sexual experience was likely to have been.

Gaulin speculates that an evolutionary fight is going on between natural selection, which conserves metabolic expenditure and promotes longevity, and sexual selection, which willingly trades both for extra mating opportunities. This may explain why men have such a range of muscularity. In the past, the strong man would have had better mating opportunities in the short term, but the skinny guy who outlived him could have had just as much reproductive success over the course of his longer life.

“Mr Muscle,” The Economist

Research by Paola Sapienza & Luigi Zingales (”Gender differences in financial risk aversion and career choices are affected by testosterone“) suggests that testosterone levels may explain why men dominate risky financial professions.

The researchers measured the amount of testosterone in the saliva of aspiring bankers (MBA students from the University of Chicago). They also estimated the students’ exposure to the hormone before they were born by measuring the ratios of their index fingers to their ring fingers (a long ring finger indicates high testosterone exposure) and by measuring how accurately they could determine human emotions by observing only people’s eyes, which also correlates with prenatal exposure to testosterone.

The students had to decide between a 50:50 chance of getting $200 or a gradually increasing sure payout, which ranged from $50 up to $120. The point at which a participant decided to switch from the gamble to the sure thing was reckoned a reasonable approximation of his appetite for risk.

Women and men with the same levels of testosterone generally switched at the same time, demonstrating similar risk preferences. Women who had more testosterone were more risk-loving than women with less, while the data for men at the lower end of the spectrum displayed a similar relationship. Curiously, the relationship between testosterone and risk taking was not as strong for men with moderate to high levels.

The correlation was strongest when the salivary measure of testosterone was used.

The researchers then followed the subjects’ progress after they graduated, to see what sort of careers they entered. Men were more likely than women to choose a risky job in finance but the difference was accounted for entirely by their levels of salivary testosterone.

“Risky business, The Economist

Africa is the fastest-growing and fastest-urbanising continent. Its population has grown from 110m in 1850 to 1 billion today. The average African woman born today is expected to have about 5 children, compared with just 1.7 in East Asia. In 1950 there were two Europeans for every African; by 2050, on present trends, there will be two Africans for every European.

The past 15 years have seen Africa’s fastest-ever period of economic growth, & it appears to be following the rest of the world through a demographic transition (falling birth rates as people get richer), which should increase the size (relative, as well as absolute) of their working-age population.

According to a study by the Harvard Initiative for Global Health (”Realizing the Demographic dividend: is Africa any different?” By David E. Bloom), the share of the working-age population will rise in 27 of 32 African countries between 2005 and 2015. On other continents this phenomenon has led to increased productivity.

Africa today produces less food per head than at any time since independence. Only 4% of Africa’s farmland is irrigated.

According to the UN Population Division, Africa’s overall population is 8% lower today than it would have been if its fertility rate had stayed at its 1970s level.

The use of modern contraceptives in sub-Saharan Africa is only 12% (though it has doubled since 1994). The rate in Asia and Latin America is over 40%, so contraceptive use is likely to rise sharply.

“The baby bonanza,” The Economist

The Evil-Mongering Of The American Medical Association

According to a 2007 study by McKinsey&Company, physician compensation bumps up health care spending in America by $58 billion annually,on average, because U.S. doctors make twice as much as their OECD peers.

Excessive physician salaries contribute nearly three times more to wasteful health care spending than the $20 billion or so that defensive medicine does. Other studies have found that doctors’ salaries contribute more to soaring medical costs than the $40 billion or so that the uninsured cost in uncompensated care.

In 1910, the Flexner report, commissioned by the AMA, declared that a surplus of substandard medical schools in the country were producing a surplus of substandard doctors. The AMA convinced lawmakers to shut down “deficient” medical schools, drastically paring back the supply of doctors almost 30% over 30 years. No new medical schools have been allowed to open since the 1980s.

The AMA convinced Congress to limit the number of residencies it funds to about 100,000 a year. Even foreign doctors with years of experience in their home countries have to redo their residencies–along with taking a slew of exams–before they are allowed to practice here.

Midwifery, once a robust industry in this country, has been virtually destroyed, thanks to the intense lobbying against it by the medical industry. In 1995, 36 states restricted or outright banned midwifery, even though studies have found that it delivers equally safe care at far lower prices than standard hospital births.

In most species, improved circumstances increase reproductive effort, yet as economic development gets going, country after country has experienced the “demographic transition,” in which fertility (the number of children borne by a woman over her lifetime) drops from around 8 to one-and-a-half.

Unless trends change, by the middle of the century, populations in the most developed countries will have shrunk and the number of retired individuals supported by each person of working age will increase significantly.

A study by Mikko Myrskyla, Hans-Peter Kohler, & Francesco Billari (”Advances in development reverse fertility declines“) suggests that the trend may change: as development continues, the demographic transition goes into reverse.

The researchers looked at two years 1975 and 2005, and analyzed countries using two factors, total fertility rate (the number of children that would be born to a woman in a particular country over the course of her life if she experienced the age-specific fertility rates observed in that country during the calendar year in question) and human development index or “HDI” (a measure used by the UN that includes life expectancy, average income per person, and level of education), which has a maximum possible value of one.

In 1975, of the 107 countries analyzed, the best was Canada, with an HDI of 0.89. By 2005, two dozen countries (of 240 analzyed) had HDIs above nine. In 1975, a graph plotting fertility rate against the HDI fell as the HDI rose. By 2005, though, once the HDI rose above 0.9 or so, it turned up, producing a “J-shaped” curve (the mirror image of a letter J).

In many countries with very high levels of development (around 0.95) fertility rates are now approaching two children per woman.

The nadir of fertility appears to be 1.3 children per woman but this new data suggests the ultimate outcome of development may be zero population growth.

“The best of all possible worlds?,” The Economist

Toxoplasma gondii is a parasite that lives in the guts of cats, where it sheds eggs in cat feces that are often eaten by rats. The parasites increase their odds of getting back to cats by changing the infected rats’ brains, making them less scared of cats (and so more likely to be eaten).

A new study by Jaroslav Flegr, Jan Havlíček, et. al, (”Increased incidence of traffic accidents in Toxoplasma-infected military drivers and protective effect RhD molecule revealed by a large-scale prospective cohort study“) found that subjects with high titers of anti-Toxoplasma antibodies had a probability of a traffic accident (17%) more than 6 times higher than Toxoplasma-free subjects.

“The Return of the Puppet Masters,” by Alex Tabarrok

Stephen Garcia & Avishalom Tor analyzed the results of the the Cognitive Reflection Test & the 2005 SAT exam. They calculated the average number of test-takers per venue in each state, and found that test scores fell as the number of people in the examination hall increased.

They then asked 74 university students to take a timed, easy general-knowledge quiz. Each student completed the test alone, but half were told they were competing against ten other people and the other half that they were competing against 100. All were informed that those whose completion times were in the top 20% would receive $5. Students who believed they were competing against only ten people finished in an average of 29 seconds. Those who believed they were competing against 100 averaged 33 seconds.

They then ran a 2nd experiment, & asked students to imagine they were running a five-kilometre race against 50 people and then against 500 (or, in half of the cases, the other way round). In both notional races the top 10% of competitors would get a $1,000 prize. The researchers told the students to rate, on a seven-point scale, how much faster than normal they would run in each notional race, with a one being slightly faster than normal and a seven being the fastest of their lives. The average value in the competition against 50 others was 5.4; in the competition against 500 it was 4.9. They then asked the participants a series of questions commonly used by psychologists to evaluate an individual’s tendency to compare himself with others in a social environment. They found that those with the highest tendency to make such comparisons had the lowest scores in the notional race against 500 others.

“The N-Effect: More Competitors, Less Competition”

“Psyched out,” The Economist

Two years ago, a study by Carsten Wrosch (”You’ve Gotta Know When to Fold ‘Em: Goal Disengagement and Systemic Inflammation in Adolescence“) demonstrated the importance of giving up inappropriate goals — those teenagers who were better at doing so had a lower concentration of C-reactive protein, a substance (made in response to inflammation and) associated with an elevated risk of diabetes and cardiovascular disease.

A recent study by Dr Wrosch and Gregory Miller (”Depressive symptoms can be useful: Self-regulatory and emotional benefits of dysphoric mood in adolescence“) measured the “goal adjustment capacities” of 97 girls aged 15-19 over the course of 19 months. They asked the participants questions about their ability to disengage from unattainable goals and to re-engage with new goals.They also asked about a range of symptoms associated with depression, and tracked how these changed over the course of the study.

Those who experienced mild depressive symptoms could disengage more easily from unreachable goals. They also proved less likely to suffer more serious depression in the long run.

The prevalence of inappropriately optimistic persistence may help explain why the US has the highest depression rate in the world.

“Mild and bitter,” The Economist

Angus Maddison has estimated that life expectancy during the first millennium AD averaged about 25 years (lots of children died very young and many of the rest survived to middle age). Many more children survived into adulthood after the Industrial Revolution and by the beginning of the 20th century average life expectancy in America and the better-off parts of Europe was close to 50. By mid-century the gains from lower child mortality had mainly run their course & the extra years were coming from higher survival rates among older people. The UN thinks that life expectancy at birth worldwide will go up from 68 years at present to 76 by 2050 and in rich countries from 77 to 83 (women generally live 5-6 years longer than men).

Jim Oeppen and James Vaupel have charted life expectancy since 1840 (”Enhanced: Broken Limits to Life Expectancy“), joining up the figures for whatever country was holding the longevity record at the time, and found that the resulting trend line has been moving upward by about 3 months a year.

In the US, centenarians are the fastest-growing section of the population, with an increase from 3,700 in 1940 to over 100,000 now.

According to Robert Fogel, Western people’s average body size has increased by 50% over the past 250 years. And larger body size is correlated with better health and longer life.

“A world of Methuselahs,” The Economist