There’s a new study out that’s been getting some media attention. In the study, researchers found that people who are more optimistic are more likely to make it to the age of 85, adding more evidence for a link between optimism and longevity.

One thing that sets this study apart is its scale. The researchers studied two cohorts of older adults spanning tens of thousands of people, with follow-up periods of 10 and 30 years respectively.

The main takeaway of the study is that people with a more positive view of the future are apparently more likely to live to see that future. This finding has been covered on a number of different media outlets, from Scientific American to BBC News.

What these articles haven’t covered as much is why an upbeat view of life can apparently make a difference in whether you make it to the middle of your ninth decade. To be clear, the study didn’t address this question – understanding why some people live longer is far more complex than establishing the fact that they do live longer in the first place.

Still, the authors of the study speculate about possible reasons for the findings in their paper, and some of the theories they discuss are interesting.

The most obvious reason that optimism is associated with longevity might be that optimists have healthier habits, such as being more physically active, eating healthier food, and drinking less alcohol. In their study, the researchers did find some evidence that lifestyle partly accounted for optimists’ longevity, but it didn’t seem to be the whole story.

Another reason is that optimists might respond to stress differently. This could be true in both a psychological sense, that they perceive stressful events differently, and a physical sense, that their bodily reactions to stress are ultimately different. For example, the authors suggest that optimism could help with “reframing situations as challenges rather than threats.” And as I’ve written about before, optimists’ levels of the stress hormone cortisol seem to stabilize more quickly after a stressful event.

Optimism can also help with establishing social connections. As with lifestyle, the researchers did find some evidence implicating different levels of social integration in the link between optimism and longevity. Once again, though, social integration only explained part of the effect.

The researchers cite a number of studies that offer support for all these possible interpretations, which you can find in their paper.

Whatever the reason for the for the link between optimism and longevity, here’s some news we can all feel optimistic about: optimism apparently isn’t fixed, with so-called optimism interventions having the ability to boost levels of optimism. So in that sense, the fact that having a positive attitude is apparently good for our health is something that we can all have a positive attitude about!