Genes and environment balance each other

Combatants in the age-old battle of nature versus nurture may finally be able to lay down their arms. On average, both nature and nurture contribute roughly equally to determining human traits.

Researchers compiled data from half a century’s worth of studies on more than 14 million pairs of twins. The researchers measured heritability — the amount of variation in a characteristic that can be attributed to genes — for a wide variety of human traits including blood pressure, the structure of the eyeball and mental or behavioral disorders.

All traits are heritable to some degree, the researchers report May 18 in Nature Genetics. Traits overall had an average heritability of 49 percent, meaning it’s a draw between genes and environment. Individual traits can be more strongly influenced by one or the other.