Editor’s note: Brain Basics from Scientific American Mind is a series of short video primers on the brain and how we feel, think and act. Below is a synopsis of the seventh video in the series written by a guest on this blog, Roni Jacobson, a science journalist based in New York City.
By Roni Jacobson
The study of behavioral genetics represents a modern take on the classic nature-versus-nurture debate. Behavioral geneticists have traditionally studied twins to gauge how much of our behavior is shaped by our genes and how much by our environment. In a 1981 experiment demonstrating the power of genetics, researchers at the University of Minnesota studied 80 pairs of identical twins who were raised apart. Despite their different upbringing, identical twins--who have virtually identical DNA--were surprisingly similar in intelligence, personality, career and leisure interests and social attitudes.
Today, behavioral geneticists aim to determine which genes influence which traits and behaviors. They use techniques such as DNA scanning and genome sequencing to find variations in the genetic code in a population and correlate these with observable traits. This approach can reveal the genes that put people at risk for different forms of mental illness and maladaptive traits such as learning disabilities. Such knowledge could enable individuals to take measures to prevent certain diseases before they develop. As we associate specific gene variants with personality traits such as extroversion, say, or talent in math or athletics, we may increasingly enable parents to screen their fertilized eggs for the array of features they desire. To what extent attempting such genetic selection is wise, or even moral, is a matter of debate.
Other Brain Basics videos: