The debate over which is more important, nature or nurture, has been raging for decades - but a new study has hinted on the answer: it depends.

It depends, that is, on the wealth of the parents:

In children from poorer households, the choices of parents still mattered. In fact, the researchers estimated that the home environment accounted for approximately 80% of the individual variance in mental ability among poor 2-year-olds. The effect of genetics was negligible.

The opposite pattern appeared in 2-year-olds from wealthy households. For these kids, genetics primarily determined performance, accounting for nearly 50% of all variation in mental ability. (The scientists made this conclusion based on the fact that identical twins performed much more similarly than fraternal twins.) The home environment was a distant second. For parents, the correlation appears to be clear: As wealth increases, the choices of adults play a much smaller role in determining the mental ability of their children.

Jonah Lehrer wrote about the intriguing study over at Wall Street Journal: Link