The Huffington Post – Carolyn Gregoire 
Humans are dynamic beings — the result of a complex web of inherited traits and environmental factors. So does nature or nurture ultimately dominate over nurture in determining our differences as individuals? It may be a toss-up. A major review of studies on twins published last year in the journal Nature Genetics found that 49 percent of the average variation for human traits and diseases comes down to genetics, while 51 percent was due to environmental factors. As scientists continue to debate the influence of nature versus nurture, psychologists at the University of California, Santa Barbara sought to uncover whether the scales tip in one direction or another when it comes to intelligence.(more)