All posts filed under: Genetics

Epigenetics Has Become Dangerously Fashionable

For the past few years, social scientists have been buzzing over a particular topic in molecular biology—gene regulation. The hype has been building steam for some time, but recently, it rocketed to the forefront of public discussion due to a widely circulated piece in the New Yorker. Articles on the topic are almost always fascinating: They often give the impression that this particular area of biology stands poised to solve huge mysteries of human development. While that conclusion may be appropriate in fields like medicine and other related disciplines, a number of enthusiasts have openly speculated about its ability to also explain lingering social ills like poverty, crime, and obesity. The trouble is, this last bit isn’t really a feeling shared by many of the genetics experts. Social scientists’ excitement surrounds what we can refer to broadly as transgenerational epigenetics. To understand why social scientists have become enamored with it, we must first consider basic genetics. Many metaphors exist for describing and understanding the genome; they all capture the reality that genes provide the information …

Not Everything Is An Interaction

Albert Einstein was a brilliant man. Whether his famous equation of E=mc2 means much to you or not, I think we can all concur on the intellectual prowess—and stunning hair—of Einstein. But where did his brilliance come from? Environment? Perhaps his parents fed him lots of fish (it’s supposed to be brain food, after all). Genetics? Surely Albert hit some sort of genetic lottery—oh that we should all be so lucky. Or does the answer reside in some combination of the two? How very enlightened: both genes and environment interact and intertwine to yield everything from the genius of Einstein to the comedic talent of Lewis Black. Surely, you cannot tease their impact apart; DNA and experience are hopelessly interlocked. Except, they’re not. Believing that they are is wrong; it’s a misleading mental shortcut that has largely sown confusion in the public about human development, and thus it needs to be retired. Despite strong genetic influences on IQ (and there are strong genetic influences on IQ), we can’t calculate the proportion of credit for Einstein’s intellect that …

A Tale of Two Bell Curves

“The great enemy of the truth is very often not the lie, deliberate, contrived and dishonest, but the myth, persistent, persuasive and unrealistic” ~ John F. Kennedy 1962 To paraphrase Mark Twain, an infamous book is one that people castigate but do not read. Perhaps no modern work better fits this description than The Bell Curve by political scientist Charles Murray and the late psychologist Richard J. Herrnstein. Published in 1994, the book is a sprawling (872 pages) but surprisingly entertaining analysis of the increasing importance of cognitive ability in the United States. It also included two chapters that addressed well-known racial differences in IQ scores (chapters 13-14). After a few cautious and thoughtful reviews, the book was excoriated by academics and popular science writers alike. A kind of grotesque mythology grew around it. It was depicted as a tome of racial antipathy; a thinly veiled expression of its authors’ bigotry; an epic scientific fraud, full of slipshod scholarship and outright lies. As hostile reviews piled up, the real Bell Curve, a sober and judiciously argued …

On Parenting and Parents

It’s been a little over a year since my first article on parenting appeared in the pages of Quillette. Soon after publication, the essay began receiving quite a bit of attention; both positive and negative. This is to be expected for a topic that is as personally relevant to people as this one. People either have children of their own, or know what it is like to be someone’s child. We all have skin in this part of the game. My argument in that essay was somewhat incendiary, as I was suggesting that little evidence exists for pervasive and long-lasting parenting influences on child development. I still maintain that position; not out of a personal bias, but simply because that is what the evidence demands of me. That said, this essay is about why parenting is arguably the single most important activity in which you will engage. This is true, not because you will mould your child’s intellect or personality like a potter. Rather, this is true because your child might write a similar essay about …

Is Crime Genetic? Scientists Don’t Know Because They’re Afraid to Ask

The U.S. has made unprecedented strides in the fight against crime. Both violent and non-violent crime are way down from their highs in decades past. This is great news, of course, but the success could easily lull us into a false sense of security, believing that we have the problem solved. Indeed, what if much of what we know about the causes of crime is either deeply flawed or flat out wrong? Imagine the trial of a new drug for an ailment that is as intractable as it is lethal. Researchers find 100 people with the disease and give the new drug to the first 50 patients who show up to the clinic. The next 50 trial participants are placed into a control group and given no treatment. The drug has a truly shimmering success rate. As you may have guessed, problems abound with this experimental design. For starters, because it isn’t randomized and because preexisting differences among the participants aren’t taken into account, the study can’t answer the question: Did the new drug cause …

If You’re Reading This Essay, You Should Probably Have (More) Children

The 20th century saw explosive population growth, fueled by a combination of declining infant mortality, decreasing violence and steady growth in agricultural productivity. These trends resulted in large part from technological advances  —  like chemical fertilizers, genetically modified food, antibiotics, and vaccines  —  which acted as a tremendous boon to human welfare. By the 1970s, some were convinced that population growth would soon lead us back to a dark age of famine, disease and war. But they were wrong. Instead of the downward spiral forecasted by Thomas Malthus, a somewhat unexpected trend emerged. Citizens of industrialized countries in the late 20th century began having fewer children. So few, in fact, that current fertility rates in Europe, Australia, East Asia and other developed regions are well below replacement levels. The result has been an aging population that faces workforce shortages and empty nests. Despite these facts, some journalists and pundits have renewed the call to have fewer kids. Why? Their main worry is climate change. A number of popular articles (and books) have implored people to …

Saints & Sinners: A Dialogue on the Hardest Topic in Science

 “Some rise by sin, and some by virtue fall” – Escalus; in ‘Measure for Measure’ by William Shakespeare There is arguably no topic more incendiary (about which scholars say less, ironically) than race differences in general, and in particular, race differences in behavior and achievement. There are certain subjects that are so politically charged and fraught with consequences that any scientific research on the topic is instantly applauded or demonized (depending on your viewpoints), no matter the findings. The subject of race differences, broadly defined, falls squarely in this category. For the purposes of this discussion, and because we are behavioral scientists, we focus on the issue of race differences in behavior. In our experience, the perception seems to be that two camps exist for the study of race differences in behavior. In the first camp, race is seen as a social construction, one that, if it is consequential, is so because of the way people react to individuals on the basis of race. Any race or ethnicity differences that emerge — for behavior, intelligence, …

Defending Liberal Eugenics: A Reply to Krimsky

We are delighted Professor Sheldon Krimsky agreed to engage in a fruitful debate with us. While we appreciate his candid critique, we respectfully disagree with some of his claims and offer a defense and clarification of the views we expressed in our initial essay. I. Professor Krimsky expressed concern over our characterization of heritability. There is no doubt that the concept of heritability is often the root source of much confusion. And Professor Krimsky rightly points out aspects that are generally true about heritability — including the fact that’s it’s a component of trait variance (one reflecting the role of genetic differences in human variation) and that it can change depending on environmental circumstances. Heritability is not written in stone (nor does it mean the same thing as “inherited”). We concur fully on these points, which is why we did not suggest anything different in our first essay (though we disagree that things like the equal environments assumption are very problematic, in practice). The reason we brought up heritability is because— while it is all …

A Response to Boutwell and Anomaly’s “Why Sex (Really) Matters”

The essay by Anomaly and Boutwell begins by emphasizing the importance of sex and ends by asserting that sex and reproduction are done for different reasons and I would add increasingly by different methods. These statements are generally recognized as true. However their statements about heritability, the genetic basis of behavior, and IQ are regrettably ill-informed, exaggerated or trivialized and are not grounded in good or consensus science. Let’s take heritability. It is a population measurement of a proportion, namely the measurement of a variation in a phenotype (physical characteristic or behavior) due to a genetic variation in a population. So if we have genetically identical plants (no genetic variation) and we find a variation in their heights, then the heritability is zero. H2 =   Var (G)/Var (P). The concept of heritability refers only to traits that differ among individuals. A trait that is exactly the same may be inherited, but it is not heritable. Also, heritability tells us nothing about individuals. Also, you cannot measure heritability without studying the environment. By changing the environment, …

Why Sex (Really) Matters

There is no more important topic in the social sciences than sex. The truth of this assertion is linked to two indisputable facts: sex often produces babies, and babies are not born blank slates. Though remnants of the Tabula Rasa myth still haunt the periphery of developmental science, a large portion of the scientific community (and increasingly, the public) has finally squared with the fact that human individuality is partly governed by genes. Put differently, part of the reason people differ from each other on measures of personality, intelligence, and temperament is because they are genetically different from one another. Because people vary genetically, our choices about who to have children with are immensely important, both for our children, and for those who will share the planet with them. Yet for many, recognition of just how critical reproductive decisions are seems to shift into gear only after a child is conceived. At that point, many of us are concerned with the mother’s ability to secure an abortion safely and without duress (within certain parameters), if …