How to maximize the surprising upsides to aging

Laura Carstensen, founding director of Stanford University’s Center on Longevity, says research has made surprising discoveries about the way older people view their lives. With fewer “what-ifs," they appear to gain more clarity on their place in the world.

The number of Americans living to at least 100 is expected to quadruple over the next 30 years, to about 422,000 by the mid-2050s, according to the Pew Research Center.

Carstensen, who is 71 and a professor of public policy and psychology, says changes will be needed to make the most of those added years. She talked with The Wall Street Journal’s Future of Everything podcast about how we could rethink life’s traditional milestones.

What do you think most people get wrong about aging and mental health?

Most people believe that growing older is associated with loneliness and depression and anxiety, that mental health suffers. The very good news is, it looks like people do better emotionally as they get older. This has been so surprising to researchers and to the general public that it’s probably been the most scrutinized finding about aging.

A lot goes wrong as we get older. There are physical problems, losses of loved ones, age discrimination. There’s a lot that isn’t good about growing older, but people seem to do better emotionally. Older people have shorter time horizons. For many years, people thought that must make people miserable and scared. The interesting thing is there’s a paradox. It actually makes people feel calmer not to have to prepare for this long and nebulous future, to be able to live more in the present.

So the Stanford Center on Longevity has developed an initiative you call “the new map of life." What is that?

The premise of the center is that longer lives are a great gift of time. But what we’ve done with these longer lives is to basically make them fit into our existing life-course ideas, so the only stage of life that actually got longer is old age. It doesn’t appear to be good for individuals or governments or societies to have a large group of people kind of sit it out for 30 years. What we need to do is to rethink how we live our lives from the beginning all the way through, in order to optimize these longer lives.

So how should we rethink our lives, and how we spend our time during our best years?

We should make childhood longer, make high school longer. What if we had two years off during high school? One year you’d volunteer in the community, so it’d be some sort of public service. And the other year you might serve as an intern in a workplace that you think you might like to end up working in.

Let’s say we don’t retire at 65 as a matter of course. Instead, we would have a new norm where people retired, but it was when they got sick or impaired physically or just couldn’t stand the job anymore. Instead of working the way we do now, we’d work, say, four-day workweeks and six-hour days. At certain times in life, for example when you might have young children, people might go down to 30-hour or 20-hour workweeks. Together, two parents might be able to split child care and we could raise our own children instead of outsourcing them and having one person working mostly just to pay for child care.

We need to rethink education. If we’re going to work for another 30 years, it doesn’t make sense to end our educations in our late teens or early 20s.

At the same time, there are some stressors that older people are more likely to deal with than younger people—your body aging, loneliness, often financial stress.

Humans are pretty good at dealing with the cards we’ve been dealt, but humans are not very good with the “what-ifs." And young adulthood and middle age are just filled with what-ifs. The older we get, the more certain and the more predictable life feels. Even when it’s not particularly appealing, at least it’s more predictable.

One of the things that’s important to keep in mind is, life is hard at all ages. So when we say that older people are doing better than younger people, I don’t mean older people are not ever experiencing negative emotions. It’s just they’re doing relatively better. Losing a loved one, having a physical disability—all of those things have been looked at and compared, younger and older adults facing the same kinds of problems and challenges. And older people tend to do better than younger people with those specific kinds of problems.

Why is that?

We’ve done some work in this area where we sample people throughout the day. We have them carry a pager, and we page them: Right now, what are you feeling? Are you thinking about the future, the past, the present?

Younger people are almost always thinking about the future. They almost always have one foot out the door, whatever they’re doing. And older people seem to do better just being able to be in the present and enjoy the moment. I think that is because they don’t have to keep planning. As people get older, it’s clearer where they stand in the world and what they’re good at. It becomes easier to say: “Yeah, you know, I’m good at this. I’m not so good at that. And it’s OK."

And older people tend to look at the positive in life. There’s a lot of evidence that when you show younger and older people different kinds of stimuli, and then later you ask them which ones they remembered, older people remember many more of the positive images than negative images. And younger people do the opposite.

What’s different about dealing with mental illness as an older person compared with when you’re younger?

Some people have psychiatric disorders and they’re less likely to receive treatment than younger people are, in part because of these stereotypes that old people are just miserable. There was a longstanding belief in psychiatry and psychology that it was more difficult to treat older people, that it was harder for them to learn new things, so it would be harder for them to respond to, say, cognitive behavioral therapies. There has now been a lot of research into that very question and it’s not the case—older people do respond to both cognitive and behavioral kinds of interventions and pharmaceutical ones. They’re less likely to be referred for treatment and less likely to actually be able to access that treatment and benefit from it.

To take a step back, what does a future world with more older people look like?

Where we are headed now is a population that is fairly evenly represented across age. We could imagine a world, let’s say, in the 22nd century, where people are expected to live their full lives and to be functionally healthy for most of it. It’s a remarkable gift. Science and technology can help us get there.

It won’t be a gift unless we also change society and the cultures that guide us through life. We need to change the norms. It will be good for older people and much better for younger people and the societies they live in if we can tap the skills and the assets that people have at different stages in life.

This interview has been condensed and edited.

Write to Danny Lewis at daniel.lewis@wsj.com