The two things that affect individuality are nature and nurture. Nature includes inherited traits such as physical apperance. Nurture includes triats that are specific to your environment, such as income, and how you are interacted with by your parents at a young age.

I think the answer they’re looking for is genetics and environment (aka nature and nurture). Research on identical twins raised apart — adopted at birth by different couples — demonstrates that genetics plays a larger role than previously thought, and the twins often display amazingly similar tastes in music, food, and other choices despite radically different home lives. And even non-twin siblings raised by the same family, as are most brothers and sisters, although presumably sharing an identical environment, are far from carbon copies of one another. The bottom line is that genetics and environment interact, with the former setting limits of a sort (for example, if you’re born with short legs it’s highly unlikely you’ll end up in the NBA) while the latter provides the setting in which we test those limits.

nature and nurture.