Nature vs. Nuture
purepedantry | July 2, 2008Publishing in Science, Gormley et al. compared the benefits of Oklahoma's TPS pre-K program to Head Start. Conclusion: preschool matters in cognitive development.
Early childhood education programs in the United States face enormous challenges. The overwhelming majority of Head Start program participants are poor, and many Head Start children face additional risk factors, such as a single-parent home or a home where English is not the primary language spoken. Pre-K programs targeted to poor or otherwise at-risk children face similar challenges. Even universally available programs, such as…
purepedantry | April 9, 2008I saw this news story in Nature a couple days ago about finding a gene for "ruthlessness." I realized that I always say the same thing about these behavioral genetics stories -- stories where they claim to find a gene for ____ (where blank is a behavioral abstraction like empathy). These studies are notoriously misinterpreted by the media, so I figure I will reiterate some caveats to remember about them.
In this study, Knafo et al. compared performance in the Dictator game to genotype for a particular allele of the vasopressin receptor AVPR1a.
In the Dictator game -- which isn't much of a…
purepedantry | August 10, 2007Nicholas Wade reports in the NYTimes about a UCD professor, Gregory Clark, and his theory of the Industrial Revolution. His answer is that high fertility rates in the upper classes caused them to steadily supplant lower classes. They brought productive values with them such that when the population reached a critical mass of individuals with middle class breeding so to speak, the Industrial Revolution occurred:
A way to test the idea, he realized, was through analysis of ancient wills, which might reveal a connection between wealth and the number of progeny. The wills did that, but in…
purepedantry | May 10, 2007The NYTimes ran an excerpt of a book called Rethinking Thin: The New Science of Weight Loss -- and the Myths and Realities of Dieting by Gina Kolata. Having read the excerpt -- I haven't read the whole book -- I take issue with how Kolata frames the issue of the genetics of obesity.
My problem with most articles and books discussing genetics -- particularly with respect to behavior -- is that they don't emphasize the concept of an environmental X genetic interaction in determining outcome. It's either all genetics or all environment.
Before, I talk about the genetics of obesity and the…
purepedantry | April 9, 2007I just thought this paper was kind of cool. It reviews the evidence from twin studies that shows that certain regions of the brain show very high levels of genetic heritability. Heritability, as I discussed in an earlier post, is a gross measure of the genetic as opposed to the environmental contribution to a particular trait. It is calculated by what are called the concordance rates between monozygotic and dizygotic twins for a particular trait -- the concordance is the percentage of twins that share the trait. (I would hasten to point out that this is not a perfect measure by any…
purepedantry | January 23, 2007Recently this model, Gisele Bundchen, speculated that the fashion industry is not to blame for anorexia. Rather parents are to blame:
Gisele Bundchen has entered Brazil's growing debate over anorexia, saying families are to blame _ not the fashion industry.
"I never suffered this problem because I had a very strong family base," the supermodel told the local Globo newspaper on Friday. "The parents are responsible, not fashion."
Top model Giselle Bundchen wears a creation part of the Colcci fall-winter fashion collection during the Fashion Rio 2007, in Rio de Janeiro, Friday, Jan 19, 2007.…
purepedantry | December 28, 2006The Economist has an article that wonders whether new knowledge into neuroscience and more particularly social pathologies will erode our belief in free will. I roll my eyes every time I read an article like this one, mostly because they tend to express an uniformed view about how the brain works:
For millennia the question of free will was the province of philosophers and theologians, but it actually turns on how the brain works. Only in the past decade and a half, however, has it been possible to watch the living human brain in action in a way that begins to show in detail what happens…
purepedantry | November 13, 2006I see that Simon Baron-Cohen has a piece in Seed about his theory of autism. I am really skeptical of many of his arguments related to autism, so I thought I would discuss a couple of them. Here is his core argument:
So what has all of this got to do with autism? We know that autism runs in families, and that if a child with autism is a twin, the chances of the other twin also having autism is much higher if the twins are identical. This tells us that genes are likely to be an important part of the explanation, and that one should look at the parents of children with autism for clues.…
purepedantry | September 5, 2006Rebecca Saxe of MIT reviews Encounters with Wild Children by Adriana Benzaquen about historical confrontations with so-called wild children -- children raised outside of society without supervision or what the author calls the forbidden experiment. The occurence of wild children has always been a bugaboo of developmental psychologists and philosophers who ask: what is the human nature in its uncorrupted (or unredeemed depending on point of view) state?
However, the review and the book both suggest that historically and most likely categorically, the wild children form an inadequate…
purepedantry | August 31, 2006I have posted before about how I think that the role of genetics, at least in popular culture, has been overemphasized. Rather, the really interesting and important parts of genetics are the ways in which your genes interact with environmental factors.
There is an excellent article in the NY Times today about how longevity has a lot less to do with genes than people think. To wit:
The scientific view of what determines a life span or how a person ages has swung back and forth. First, a couple of decades ago, the emphasis was on environment, eating right, exercising, getting good medical…
purepedantry | July 30, 2006This review in Nature Neuroscience is excellent. I have never seen the issue of gene-environment interactions laid out so eloquently. Unfortunately, it is behind a subscription wall, so those of you not affiliated with a University may have to just live with this excerpt:
The recent history of psychiatric research that has measured genetic differences at the DNA sequence level can be divided into three approaches, each with its own logic and assumptions. The first approach assumes direct linear relations between genes and behaviour (Fig. 1a). The goal of this approach has been to correlate…
purepedantry | July 9, 2006Jonah at The Frontal Cortex posted a great article exposing the limits of genetic determinism. Sometimes a genetic explanation seems so obvious, but further study shows that environment also plays a prominent role. Definitely read the whole thing.
purepedantry | June 18, 2006As promised I have a response to this article in the New York Times (I had to spend a couple days marshalling my evidence). I thought I would summarize some evidence about what we know from behavioral genetics so you could understand why I think this article was so wrong. I have tried to classify what we know below by the kind of study that we use to know it. Hopefully this will make things a little bit more clear.
(WARNING: This post is what economists would call a Schumpeterian tome.)
People studying behavioral genetics in humans use three types of studies:
Twin studies: Twin studies…
purepedantry | June 15, 2006I was totally incensed by this article in the New York Times, largely because the science quoted -- what little there was in between the anecdotes -- was truly attrocious, ignorant of alternative views, and completely missing the point.
When I get a free moment I will provide some clear examples of why genetics is a factor in determining behavior but only in an environmental context. Until then Cognitive Daily and The Frontal Cortex seem to be confronting the issue quite ably.
purepedantry | June 9, 2006This article in Science News is really interesting as it goes into the causes of disruptive behavior in children. I don't have much time to review it now as I have the last test of my graduate school life in about an hour and a half, but I think it cuts a good balance between saying that genes matter and saying that they matter in an enviromental context.
I will be doing the happy dance with more posts later.