DNA IS NOT DESTINY

Does the human genome include a thread for the likelihood of falling for hype? If it does, then it would be fine vindication for this sharp book on the limitations of genetics in understanding what makes us tick.

What makes people tall? What makes people smart? What makes some people more likely to develop breast cancer than others? The common shorthand these days would be to lay blame or responsibility, depending on the matter at hand, on one’s genetic makeup. However, as Heine (Social and Cultural Psychology/Univ. of British Columbia; Cultural Psychology, 2007) writes, that’s a two-edged sword of an answer, for while understanding genetic issues has led to some moments of détente in the culture wars—e.g., acceptance of homosexuality as an expression of biology—it is also not necessarily complete. For instance, he argues, genetics itself cannot fully explain why people grow taller when their diets improve or why people raised by affluent adopted parents score higher on IQ tests than their less affluent peers. Such issues can be thorny, and to his credit, Heine does not shy away from them even as he takes on the popularity of consumer-level genomics to predict the propensity for disease, which he reckons to be about as accurate as “the fortune-teller down the street, and at least she isn’t claiming any scientific foundation to her predictions.” The author is generally affable, but he also is impatient with pseudo-science; he writes, for instance, that the more people actually know of genetics the less likely they are to be worried about genetically modified food, while terms such as the “breast cancer gene” or the “height gene” are worse than misnomers, since many more genes than one are implicated. To increase a baby’s height, by Heine’s reckoning, you would need to effect “almost 300,000 genetic alterations to the embryo, and you would still only be halfway there.”

An accessible contribution to what the author calls “genetic literacy” and a satisfyingly hard-edged work of popular science.