Although in this chapter we have addressed why, when and where individuals are optimistic, individual differences theorists are still unsure of how optimism occurs. In other words, there is still confusion over where optimism actually comes from; its origins are unclear. It is believed that the genetic heritability of dispositional optimism is estimated at an average of .33 across the population (Scheier & Carver, 1985). In other words, an estimated average of 33 per cent in dispositional optimism across the population is thought to be accounted for by genetic influences. We can of course presume the rest of the variance is accounted for by factors involving environmental influences. However, there are no clear theories as to what the factors are, other than that they are simply learned or they occur in situations.
Can you identify certain environmental factors or processes that may influence optimism?