Are Humans Getting Dumber (or is it Just Journalists and Sociobiologists?)

Human intelligence is on the decline, according to the Huffington Post, writing about a recent study suggesting that westerners have lost 14 I.Q. points since the Victorian Era. Study co-author, Dr. Jan te Nijenhuis, professor of work and organizational psychology at the University of Amsterdam, says that because women of higher intelligence tend to have fewer children than do women of lower intelligence, intelligence is being selected out of the affluent populations of the west.

The Kallikak family, promoted by eugenicist Henry Godard as proof of heritability of idiocy

There are probably many on the Left who would like to jump on these findings as an explanation for everything from the high numbers of Americans who believe in creationism or who deny climate change to the continuing popularity of the Republican Party among people devastated by their economic policies.

The problem is that this study and all others pointing to a causal relationship between birthrates and IQ are seriously flawed. Indeed, even the claim that IQs are declining is suspect.

Alfred Binet

Let’s start with the fact that the IQ test, developed by Alfred Binet, in France, wasn’t even created until 1903, two years after Victoria’s death, making it exceedingly difficult, if not impossible, to make a valid comparison of Victorian and modern Westerners’ IQs. Furthermore, the original test emphasized memorization, vocabulary and questions about appropriate behavior, none of which has much to do with intelligence. Even modern versions of the test contain some of these types of questions. IQ tests also tend to have a class bias, as well as cultural and linguistic biases (e.g., questions about appropriate behavior depend on one’s cultural background).

To address this problem, te Nijenhuis used proxies for intelligence (comparing a variety of different tests for which data does exist going back to 1884). However, he chose a very weak proxy, reaction time, which he presumed was an accurate proxy for intelligence since reaction time reflects a person's mental processing speed. However, it is not necessarily true that a person who has a quick visual reaction rate also has a quick mental processing rate for math, puzzles or other types of problem solving.

Another problem with the research is that it lacked valid controls, drawing into question the validity of the comparisons. Supposedly the Victorian and modern experiments used a similar test for reaction times, but they used different instruments for measuring the results. Thus, the average late 19th century reaction time of 194 milliseconds might have actually been much closer to or even slower than the average 2004 reaction time of 275 milliseconds had researchers used the same equipment and methods.

 

1920s pseudoscientific image trying to connect brain types to criminality

Bad Science in Service to Race and Class Prejudice

The researchers also used data collected by Francis Galton (Darwin’s cousin), who coined the term eugenics, which included the idea that poor people were poor due to their inferior intelligence, which they presumed was due to their “bad” genes, and that the affluent were wealthy due to their good genes. This pseudoscience was used to justify government interventions promoting or limiting birthrates among different races and social classes, forced sterilizations in many countries, including the U.S., infanticide, and genocide, as practiced by the Nazis. Thus, Galton had a significant bias going into his research, specifically an Experimenter’s Bias (i.e., observing what you expect, rather than what actually occurs). In Galton’s case, he would be expecting white and affluent people (who also had smaller families) to be smarter, and could have inadvertently designed tests that would have given him these results.

 

Image from Wikipedia, based on Galton's Ideas

Te Nijenhuis’s research suffers from some of these same problems, particularly the presumption that intelligence is essentially a heritable trait (i.e., passed through the DNA), a presumption still shared by a large number of scientists as well as the lay public, despite a lack of credible data to support this idea (more on this below). However, his race and class prejudices also come out in his belief that “high-IQ people are more productive and more creative,” and his nostalgia for the flourishing of creativity and brilliance of the Victorian era. He uses the term dysgenics in his work, a term that is often associated with the eugenics movement thanks to the work of Richard Lynn, who argued in his book Dysgenics: Genetic Deterioration in Modern Populations, 1996, that human genetic health was declining because criminals have higher birthrates than the rest of the population (there is no evidence they have higher birthrates and it is unlikely that criminality is heritable), leading many, including Lynn, himself, to renew calls for eugenic policies.

 

Many states had similar sterilization laws, resulting in 10,000s of forced and voluntary sterilizations in the 20th century

Genetics is Not Destiny

While large numbers of scientists and the lay public believe that intelligence is highly heritable, there is no conclusive evidence for this. Indeed, estimates of the heritability of IQ range from as low as 40% to as high 90%, suggesting that intelligence is at least partly, and possibly quite significantly, influenced by factors other than DNA. Part of the reason why there is so much controversy over the degree to which intelligence is heritable is that no genes for intelligence have been positively identified, (though recent research has located positions on certain chromosomes where some genes related to intelligence might be located).

Intelligence and IQ, like most phenotypes (traits), are influenced not only by DNA, but by environmental influences and sometimes even by random events that occur during development. ABO blood type, for example, is 100% heritable, meaning that it is determined entirely by the DNA inherited from the parents and no environmental factors influence it. Human height is around 94% heritable. However, even a relatively high heritability of 94% is not sufficient to presume a cause and effect relationship between DNA and a particular phenotype. A person with tall parents could easily wind up being short if he does not have access to a diet rich in protein and calcium. Indeed, when one considers stereotypically short ethnic groups, most come from regions of the world with high levels of malnutrition in which protein and calcium are relatively scarce. Similarly, average human heights in Western Europe and the U.S. have increased 4” over the past 150 years, according to Scientific American, most likely because of improvements in childhood nutrition that occurred during that period.

There are many environmental factors that influence learning, memory, and even reaction time. Memory and reaction time, for example, can be improved with certain exercises and practice. Exposure to high levels of stress can impair memory and learning due to overexposure to the stress hormone cortisol (see here, here and here). How parents communicate with infants and children can influence the size and depth of their vocabularies (see here and here), which can influence how they comprehend phenomena and their ability to solve problems. Malnutrition and hunger can lead to cognitive impairment (see here, here and here).

Another problem with te Nijenhuis’ findings is that low IQ parents, while they may have larger families, do not necessarily produce low IQ children (“Resolving the debate over birth order, family size, and intelligence,” Rodgers, Joseph Lee; Cleveland, H. Harrington; van den Oord, Edwin; Rowe, David C. American Psychologist, Vol 55(6), Jun 2000, 599-612).

Confusing Correlation With Causation

Despite the fact that te Nijenhuis is a scientist, he apparently has difficulty distinguish between correlation and causation. There is considerable evidence that populations with higher IQs have lower birthrates. Thus, I.Q. and birthrates have a negative correlation (i.e., as one goes up, the other declines). However, this does is not evidence that one is caused by the other. Rather, they could both be products of one or more other causes or the correlation could simply be a coincidence.

Social class also correlates with both birthrate and intelligence. Wealthier women tend to have fewer babies. There are several logical explanations for this such as delaying motherhood to pursue college and career, for affluent women, versus having children earlier and more often among poor women because children can help with the farm work and care for you in your old age.

Wealthier people, in general, also tend to have higher IQs. However, this may have far more to do with environmental and social factors (e.g., access to better nutrition and healthcare, better quality schools, being read to more often as babies and toddlers, less stress, greater access to enriching extracurricular activities, like travel abroad, summer school and camps) than genetics. Indeed, two studies done in Texas and Minnesota seem to support this. According to the studies, the correlation in intelligence between mothers and biological children were not only quite low (0.20 to 0.34, respectively), but not much different than the correlations between mothers and adopted children (0.22 to 0.29, respectively), suggesting that social and environmental factors likely had a greater influence on children’s intelligence than the genetics of their mothers (Richard Lewontin, Not In Our Genes). In other words, intelligent people may very well be intelligent more as a consequence of their social class privileges than their parents’ genes.

Work Hard, Study Hard and Still Get Left Behind

The American Dream mythology says that if you work hard and play by the rules you can be a success. This mythology ignores the fact that people born into affluent families have a far greater chance of attaining financial success than people born into lower income families precisely because of all the advantages and privileges that come with affluence. Those who rise out of poverty and achieve the American Dream are extremely rare and the exception to the rule.

A new study, “Working Hard, Left Behind,” by the Campaign for College Opportunity, found that over 33% of California families are low income (earning less than $45,397 for a family of four) despite their hard work. The state currently ranks #1 in the nation in the number of working poor families. The solution, the Los Angeles Times argues, is higher education. Since Californians with Bachelor’s degrees earn $1,340,000 more in their lifetimes than those with only high school diplomas, making everyone go to college would necessarily solve the problem, right?

According to the Times, the study found that “higher education is a proven pathway from poverty to prosperity for working Californians.” However, in science we generally require a high level of evidence before we can say we have proof and the evidence simply isn’t there to say that higher education is a “proven pathway to prosperity.” Consider all the unemployed people with higher degrees.

Both the Times, and apparently the researchers at the Campaign for College Opportunity, have confused correlation with causation. Yes, people with college degrees do tend to earn more than those who lack them, but that doesn’t mean that the degree is the cause of their financial success. Affluence increases the chances that a person will do well in grades K-12, increasing the chances of getting into a four-year college and succeeding there, as well. While college achievement does indeed correlate with future financial success, affluence correlates with both academic success and financial success. Thus, it is entirely possible, indeed likely, that familial wealth is the cause of future financial success, in part because it increases the chances of academic success.

The conflation of correlation with causation has led the Times and the Campaign for College Opportunity to some absurd policy prescriptions, like proposal that we increase enrollment of low income adults in colleges, while doing nothing to directly address their poverty. Of course it would be wonderful if the state were to increase funding for its universities and community colleges and provide the financial aid so that every adult in the state could attend college, or even just provide childcare for single mothers, but this would not solve the problem for several obvious reasons. Many low income adults lack the prerequisite skills to succeed in college, including literacy, self-confidence, and study skills. Indeed, many have the equivalent of an elementary school reading level or a long history of academic failure. Many are working full time to support their families and simply lack the time and energy to complete college classes on the side.

Considering that a wealth-based achievement gap exists by the time children are three (and it tends to grow as children move through the education system), it would be a lot more efficient to invest in programs that reduce poverty and material insecurity for families, that encourage parents to read and play with their children, that improve perinatal and children’s health, as well as preschool programs that prepare kids for kindergarten. This would front load the system by increasing the number of people graduating high school with the skills to succeed in college.

However, there is another problem with the Time’s and the Campaign’s reasoning: Even if everyone graduated from college there would continue to be a significant wealth gap. Want and privation are products of wealth and privilege, which in turn are products of an economic system based on exploitation. So long as there is an employing class that pays its employees only a fraction of the value of the goods and services they produce, pocketing the rest as profits, there will continue to be poverty. Likewise, as long as workers accept their dependence on employers, especially without a fight, there will continue to be a downward spiral in wages for everyone, including the college educated. Consider, for example, how much the average middle class, college educated family has lost in personal wealth over the past five years, or the overall decline in living standards that has been occurring since the 1970s for all but the richest Americans.

Robin Hoodwinked by Governor Brown

The Los Angeles Times is referring to California Governor Jerry Brown as a “Robin Hood” for his plan to redistribute resources from “wealthy” suburban school districts to their poorer urban cousins. Brown has characterized himself as a civil rights hero since the poor urban districts serve predominantly low income communities of color, suggesting that inequitable school funding is the primary cause of the achievement gap.

Both the Times and Brown are delusional. Robin Hood robbed rich individuals and gave the spoils directly to poor people so they could feed, clothe and house themselves. Brown’s plan does nothing to reduce poverty and gives no money or resources directly to any poor students or their families.

This is no trivial criticism, as poverty is the number one cause of poor academic achievement. Poor children are far more likely than others to be born with low birth weight or suffer malnutrition or lead poisoning (10% of poor children have dangerous levels of lead in their blood according to the CDC), any of which can impair cognitive development or lead to learning disabilities. They suffer higher levels of stress, which causes the overproduction of the stress hormone cortisol, which can impair memory and learning. They are absent far more often (as much as 40% more, according to Richard Rothstein), dramatically decreasing their chances of graduating on time (see here). They have less access to enriching extracurricular activities like summer travel, camp and museum visits, which can cause the achievement gap to increase each year. Lower income families tend to read less to their babies and toddlers and expose them to fewer complex words and phrases, with the result that affluent children have vocabularies that are tens of thousands of words larger than their lower income peers even before they have entered kindergarten (see here and here).

As long as poverty persists, increasing resources to lower income schools will have very limited effect on student achievement. It certainly cannot remove the stress and anxiety that result from living a life of material scarcity and uncertainty and the ongoing sense of powerlessness that accompanies it.

The Times does correctly note that poor districts would not necessarily benefit at the expense of wealthy districts under Brown’s plan. Some poor districts, like Oakland, would actually receive less per student under the governor’s plan, according to both the state education department and the governor's own budget office.

It is also misleading to refer to some districts as “wealthy.”  Certainly some districts have higher percentages of affluent students, but this does not mean they are adequately funded publicly. There probably is no district in the state that receives sufficient funding entirely through property taxes and state and federal revenues. The wealthiest districts receive more money than the poorer districts, but not enough to keep class sizes under 35; hire sufficient nurses, librarians, counselors and teachers; purchase sufficient lab equipment and classroom supplies; or pay teachers’ salaries comparable to those in the private sector. Many of these schools are able to raise funds from parents to supplement what they receive from the state and local taxes, but there are also many lower income schools in so-called wealthy districts that do not have this capability.

Transferring resources from the “wealthy” districts will not come close to restoring what the poorer districts have lost as a result of the $20 billion the state has slashed from education funding over the past few years. Even if it did, that would only bring these schools back to a level that was grossly inadequate (California education spending was among the lowest in the nation even before the recession). “Wealthy” schools can always ramp up their fundraising from wealthy families, but they will continue to have overcrowded classrooms and underpaid teachers.

More significantly, Brown’s plan gives the illusion that he is doing something equitable and rational to mitigate the state’s education problems, when in reality he is simply holding education funding steady at the 46^th lowest level in the nation . This, in turn, allows the state to maintain historically low tax rates for the wealthy and their businesses and to continue defunding social programs that serve the poor, including transitional kindergarten.

California, Poorest/Richest State in the Nation

California currently has more than 600,000 millionaires and 85 billionaires in the Forbes 400 list, far more than any other state in the nation. At the same time, California is now the poorest state in the nation, with the highest percentage of residents living at or below the poverty level. According to the Census Bureau, 23.5% (8.7 million Californians) are living in poverty. Florida is number 2 at 19.5%.

These numbers reflect a revision in how the Census Bureau measures poverty. In the past, it looked solely at income versus food costs. Under this system, the poverty rate would be only 16%. Under the new system, it now considers income plus assistance programs (e.g., food stamps, welfare) versus tax rate, childcare, housing and medical costs, in addition to food expenses, providing a much more realistic (though still incomplete) picture of families’ financial challenges.

Nearly 50% of California’s children live in or “perilously close” to poverty according to the newer metric, probably the single biggest reason for the state’s low test scores. True poverty rates are further obscured by the arbitrary and absurdly low federal threshold of $23,021 for a family of four. Considering that average monthly rents are $1552 in Los Angeles, $1431 in San Diego, $1938 in San Jose and $2106 in San Francisco, families must spend between $17,172 and $25,272 per year just to place a roof over their heads.

It is not just that better methods are providing a more accurate measure of poverty. The recession has also contributed to a dramatic increase in poverty. Between 2008 and 2011, for example, poverty rose 12% in Los Angeles County to 24.3%, and rose even more in some of the state’s rural counties. Conditions have grown so bad that California has seen negative migration patterns for the past eight years, according to the WSWS. A combination of low unemployment rates in Mexico (roughly half of California’s in recent years) and increased militarization of the border and deportations (a record 400,000 in 2012) has significantly reduced migration from Mexico. This has led to labor shortages in the state’s agriculture sector, with some farmers opting to let unpicked produce rot rather than increasing wages to attract domestic employees, since the former increases sales prices and profits, while the latter only cuts into profits.

While the state’s economy “recovers,” job growth has been primarily in low-wage service jobs. Thus many formerly unemployed are now earning far less than they did prior to the recession, contributing to the ranks of the working poor. Cuts to social programs has placed further downward pressure on living standards and contributed to the growing number of poor Californians under the new measurement system.