All posts filed under: Genetics

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, …

Why Sex Really Matters Part Three: 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 …

On the Reality of Race & the Abhorrence of Racism Part II: Human Biodiversity & Its Implications

If you observe the residents of Japan and compare them to residents of the rural southern United States, you’ll note some differences. Some differences will be stark, others less so, yet they will not be isolated to religious and cultural practices. The differences that emerge will bleed into psychological and temperamental traits that also vary in noticeable ways across populations. The reason for the existence of these differences, though, admits of no simple answer. Prevailing wisdom holds that the cultural and psychological differences that exist across human population groups were shaped largely by a confluence of history, sociological forces, and pure chance. This is likely true to some degree, but the prevailing wisdom — from my point of view — is incomplete. In Part I, we argued that human races exist, meaning that humans can be meaningfully classified into coherent groups based on genetic ancestry. If we’re going to take seriously the existence of meaningful racial variation we also have to at least consider that the genetic differences that exist across racial and ethnic groups …