Perhaps a better word would have been "intrinsic". A trait can be a result of compounding, non-shared environment. For instance, at any early age you might ha

Perhaps a better word would have been "intrinsic". A trait can be a result of compounding, non-shared environment. For instance, at any early age you might have recieved a reward for taking a risk. Perhaps that led you to take more risks, and achieve more rewards. Then you join a social group in which you develop a niche as being the guy who always takes crazy risks. As a result of this, by age 20 being a risk taker is built into your personality.