Not in Our Genes

This article reaches a mostly correct conclusion but not from the strongest line of reasoning. I am blessed with the opportunity to attend the weekly behavioral genetics seminar ("journal club") at my alma mater university each week during the school year. That journal club includes many of the pioneers of the Minnesota Twin Family Study. A new book about the research conducted here has just been published by Harvard University Press

http://www.hup.harvard.edu/catalog.php?isbn=9780674055469

so readers all over the English-speaking world will get a lot of the inside story of what has been discovered in research on monozygotic ("identical") twins reared apart. In the local journal club I have learned about professional articles that dispel common misconceptions about human behavioral genetics.

Turkheimer, E. (2012). Genome wide association studies of behavior are social science. In K. S. Plaisance & T.A.C. Reydon (Eds.) Philosophy of Behavioral Biology (pp. 43-64). New York, NY: Springer.

http://people.virginia.edu/~ent3c/papers2/Turkheimer%20GWAS%...

"If the history of empirical psychology has taught researchers anything, it is that correlations between causally distant variables cannot be counted on to lead to coherent etiological models."

Johnson, W., Turkheimer, E., Gottesman, I. I., & Bouchard, T. J. (2009). Beyond heritability: Twin studies in behavioral research. Current Directions in Psychological Science, 18, 217-220. [I am personally acquainted with three of the four co-authors of this paper, one of whom regularly exchanges links with me by email.]

http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O...

"Moreover, even highly heritable traits can be strongly manipulated by the environment, so heritability has little if anything to do with controllability. For example, height is on the order of 90% heritable, yet North and South Koreans, who come from the same genetic background, presently differ in average height by a full 6 inches (Pak, 2004; Schwekendiek, 2008)."

Turkheimer, E. (2008, Spring). A better way to use twins for developmental research. LIFE Newsletter, 2, 1-5.

http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O...

"Unfortunately, that fundamental intuition is wrong. Heritability isn’t an index of how genetic a trait is. A great deal of time has been wasted in the effort of measuring the heritability of traits in the false expectation that somehow the genetic nature of psychological phenomena would be revealed. There are many reasons for making this strong statement, but the most important of them harkens back to the description of heritability as an effect size."

To sum up, the submitted article is correct insofar as it asserts that genes are not destiny in human behavior. Monozygotic twins are from time to time quite discordant even in characteristics that are deemed "highly heritable" with reference to the experience of other twin pairs. The shuffle of genes that you or I receive from parents at the beginning of life does not determine our behavior, but simply establishes a biological substrate for the "reaction surface" that each of us present to our individual environments. Other factors that are properly called "environmental," both at the societal and individual level of analysis, can and do overcome the odds influenced by individual genomes.

If you don't have a background in this area and are interested in learning a little more about epigenetics, there is a good NOVA program on it: http://www.pbs.org/wgbh/nova/genes/