Optimism is often considered a finite human resource: for the young, with all their endless opportunities, the virtue is abundant; for the old and embittered, a mere memory.
Life, it turns out, may not leave us quite so jaded. No matter how many hurdles a human may endure, a new study has found that as the years pass, we merely grow more enthusiastic about our prospects.
Among the 1,169 participants surveyed, the researchers found that optimism was at its lowest during early adulthood and highest around age 55, peaking at the same time as other attributes, like self-esteem and life satisfaction.
"There seems to be a popular perception that people become less optimistic with age, that their maturity leads them to be better calibrated to the ups and downs of life," study co-author Ted Schwaba of the University of California at Davis told PsyPost.
"But it seems, in this sample and a few others, that the lifespan story of optimism is actually one of gradual increase throughout adulthood."
For seven years, the researchers tracked a large sample of Mexican-Americans aged between 26 and 71. On four separate occasions during the study period, the participants were asked to complete a six-question Life Orientation Test - a common measure of optimism.
In addition to that, the participants also rated the truth of 54 statements about various positive and negative life events, including: "I hardly ever expect things to go my way" and "In uncertain times, I usually expect the best".
Strangely enough, the researchers found that more negative life events did not necessarily lead to a more pessimistic attitude. Instead, it was only positive life events that had any apparent sway over a person's outlook, an idea that runs contrary to many psychological theories.
As we humans navigate early adulthood, the results suggest that we tend to develop a rosier view of the world, and that's especially true if things go well for us, like graduating from college, falling in love, or getting a pay raise.
"Progressively attaining these major developmental goals may be an engine for increasing optimism throughout early adulthood," the authors suggest.
"Additionally, increases in autonomy and self-regulation ability, which allow a person to more easily execute their desired behaviours and reach desired outcomes, may lead to increases in optimism with age."
While these results did not differ among men and women, the authors did notice a discrepancy between participants born in America and those who had immigrated from Mexico.
While the majority of immigrant participants showed the inverted U-shape of optimism, peaking at age 55 before dropping off again, the few non-immigrant participants took a different path.
Among those born in the US, optimism decreased from ages 26 to 40, but then increased again from ages 40 to 71.
"These results suggest, broadly, that differences in culture, even among members of the same ethnic group, may lead to differences in optimism development," the authors explain.
"However, given the relatively small size of the non-immigrant group (only 14 percent of respondents were non-immigrants), we refrain from further interpreting this finding until more evidence emerges."
It's clear that optimism is a malleable construct, influenced by events of the past, but this is only the fourth study that has investigated how it develops.
Other studies, like one in 2013, have found the exact opposite, suggesting that future life satisfaction goes from optimistic to accurate, and then from accurate to pessimistic.
Much of this research is based on self-reporting, which obviously comes with its flaws, especially when optimists and pessimists are so wildly influenced by their points of views. It would be just like an optimist, for instance, to inflate their positive life events.
While the results of this survey certainly give us food for thought, we still know relatively little about how optimism changes with age, or any other factor for that matter - it's an area of psychology that remains ripe for research.
This study has been published in Social Psychology and Personality.