If you're an optimist, you generally believe that good things will happen to you—and that attitude can be the best kind of self-fulfilling prophecy. According to a report published in the journal Social Psychological and Personality Science that analyzed optimism across age groups, being optimistic has been linked with positive life outcomes, including better physical health and increased overall well-being. But that same study revealed that the average person's optimism (which waxes in older-adulthood) wanes past a certain age. Statistically speaking, the average person becomes a pessimist when they turn 70 years old.
The researchers examined "age differences and longitudinal changes in optimism" in 9,790 older adults over a period of four years. They found that "optimism generally increased in older adults before decreasing," they explained. "Increases in optimism over a four-year period were associated with improvements in self-rated health and fewer chronic illnesses over the same time frame."
As the research team discovered, older age was associated with lower overall quality of health. Understandably, those with lower health quality were less optimistic—meaning that crossing a threshold of more prevalent health concerns triggered a more pessimistic outlook past 70.
Graphing the study participants' dispositions on a slope, the team found that optimism was "positive from age 50 to (approximately) age 70, depicting an increase in optimism over a four-year period among individuals aged 50–70." In other words, between 50 and 70, people became more optimistic.
Yet trends in disposition hit a turning point at 70, when study subjects became more pessimistic over the four-year period. (The researchers did note that they found evidence for small increases in optimism among participants that were 95 and older, but also cautioned that their sample sizes for that age group were too small to form conclusions.)
So, when you hit 70, should you expect to suddenly view the world through a pessimist's lens? Thankfully, it doesn't exactly work that way. Any emotional shift you experience is likely to be gradual, and in response to your own particular life circumstances. If you're lucky, it will never come at all. Still, it's useful to be aware of it as a broader trend—after all, preparing for the possibility of more pessimism might be exactly what you need to lift yourself out of it. And for more on the link between optimism and health, check out 4 Easy Things You Can Do to Live a Longer Life.