If you analyze a host of real world outcomes using adoption studies, fraternal v. identical twin studies, twins-raised-apart studies, the history of early childhood intervention research, naturally-occurring experiments, differences between societies, changes over history, and so forth, you tend to come up with nature and nurture as being about equally important: maybe fifty-fifty. The glass is roughly half-full and half-empty.

Sailer, Steve (October 25, 2012). A Short, Stylized Dialogue On Epigenetics. VDARE.com. Retrieved on October 27, 2012.