Add Yahoo as a preferred source to see more of our stories on Google. A century’s worth of twin data reveals that when schooling differs, identical twins’ IQs can diverge as much as unrelated people’s ...

When you’ve just had identical twins, it’s normal to spend a lot of time looking down at their squishy little bodies and analyzing every subtle way they differ from one another. Unlike fraternal twins ...

For more than a century, scientists have debated whether intelligence is mostly a product of nature or nurture. Identical twins—those born with the same genetic blueprint—have long been the perfect ...