Sept. 1, 2006 — Genes shape our health and appearance more than they shape our personality, suggests a new study of thousands of people in a genetically isolated part of the world.
According to the study, published in the August issue of PLoS Genetics, genetics account for roughly 51 percent of a person’s height, weight and overall body shape, 25 percent of cardiovascular function, and about 40 percent of certain blood characteristics, such as sugar and cholesterol levels.
But genes only account for about 19 percent of many documented personality traits, such as neuroticism, extraversion, agreeableness and conscientiousness.
"My personal view is that we have evolved to have very diverse personalities and that, compared to other traits, personality may be much less deterministic than other human characteristics," said Gonçalo Abecasis, one of the study’s authors. "My view is that both genes and environment will play smaller roles than random factors."
Abecasis, a scientist at the Center for Statistical Genetics at the University of Michigan, and his colleagues examined 6,148 people from the Mediterranean island of Sardinia, where many residents are related.
Roughly 95 percent of all test subjects’ grandparents were Sardinian, and the test group included 5,000 pairs of siblings.
The researchers believe their study is the largest ever published for the traits they examined.
The scientists took blood samples, gave physical exams, and asked participants to fill out standard personality questionnaires. A battery of tests measured liver and thyroid function, electroylte levels, cholesterol, blood glucose and more.
