> Comparisons of data between pairs of identical and non-identical twins showed that genetics plays only a minor and insignificant role in next-day alertness, e

> Comparisons of data between pairs of identical and non-identical twins showed that genetics plays only a minor and insignificant role in next-day alertness, explaining only about 25% of the differences across individuals. What a bizarre statement. In what world is a 25% statistical effect "minor and insignificant"?