For years, midlife has been associated with one word: crisis. Margie Lachman wants us to see opportunity instead.

Lachman, a lifespan developmental psychologist, has been studying what goes on between the ages of 40 and 60 for more than 30 years, as an investigator on the landmark Midlife in the United States study. The study has tracked thousands of adults since 1994, exploring how their lives, health and perspective changed. Before joining the project, Lachman was about to turn 40 herself. “I went through midlife as we were studying midlife,” she says.

Previously, that life stage had been either maligned or overlooked as uneventful. Now a professor of psychology and director of the Lifespan Lab at Brandeis University in Massachusetts, Lachman wants to change midlife’s negative reputation. According to her research, the belief that midlife is inevitably unhappy or defined by a dramatic pivot is “flat-out wrong”. It can even be a golden run, as her own experience showed: “I’m looking back on it now, but I loved midlife,” she says.

In her new book, Primetime: A New Vision For Midlife, Lachman gives reasons to be optimistic about getting older without denying the realities. It’s not just about correcting the record: people with a positive view of ageing tend to be healthier, she says.

Our conversation has been condensed and edited for clarity.

You were barely in midlife yourself when you started studying it. What interested you about this period?

I was studying older people, 60 and above, when I got invited to join the MacArthur Foundation research network to study midlife. It just sounded intriguing, and uncharted territory. Most of the work being done in my field at the time was focused on young people and older people. We didn’t really know much about these middle years, partly because middle-aged people were too busy to come into the labs and take part in our research. Most of the existing literature was on events that happened in midlife, like divorce or unemployment, but, as a period of life, we didn’t think much was going on. Well, we were wrong.

What are the common characteristics of midlife, beyond the midlife crisis?

Typically, people in midlife have both older and younger people depending on them. On average, 45% of US adults in their 40s and 50s are in the “sandwich generation”, with a child under 18 and a parent who needs their help. Regardless of your particular family constellation, having people who count on you, who you can advise and mentor and help, is a central theme of midlife. This can be a good thing – you have a lot to offer – but it can also create a lot of pressure.

The other commonality is physical changes. As people hit their 40s and 50s, they start to see outward signs of ageing: they need reading glasses, their hair starts turning grey, wrinkles appear. That triggers concern: “Oh my God, I’m getting older.” They start thinking they don’t have much time left, or [that] it’s all downhill from here. A lot of the negative connotations of midlife stem from that.

The stereotypes of middle age are mostly negative: it’s thought of as unhappy, the beginning of the end. Your research and others’ shows this isn’t the case.

What we typically find is that life satisfaction is fairly stable through midlife and into early old age, but if anything, it goes up. People are more satisfied with their life. In fact, today younger people tend to be less satisfied [than middle-aged people], with a lot more depression and anxiety.

But if you say “midlife”, the first thing people think of is “crisis” – it’s this stereotypic, automatic response, which is unfortunate. In one study we did years ago, with older generations, about 26% said they’d had a midlife crisis, but when we asked them what they meant, they all talked about different things, like divorce, a job loss or health crisis, which could really happen at any age. In some cases, [these events] hadn’t even necessarily occurred in midlife – they came much earlier, or later. This notion has just gotten out of hand: anything that goes wrong is considered a midlife crisis.

If there’s no evidence for it, how did the concept of a midlife crisis become so entrenched?

When you start a new decade, or reach the middle of a decade – you turn 40, 45, 50, 55 – it’s a natural time to reflect. People also think of these years as the halfway point of life, so they look back and realise they haven’t met all their goals, or things aren’t going exactly the way they’d hoped.

I think that’s normal; it doesn’t mean that it’s a crisis. “Crisis” is a very strong term. Really, in a way, it’s empowering to realise you want to tweak some things, and that you have the opportunity.

Younger generations are hitting milestones like home ownership and parenthood later in life, if at all. How will that change midlife?

Now people also talk about a “quarter-life crisis”, around age 25. We hear a lot of concern from millennials about how they expected to have accomplished things like finishing education, starting work, finding a partner, having children and buying a home by now, because their gen X or baby boomer parents did. It really takes a lot longer to achieve those milestones and feel like you’re an adult now.

I think it means midlife will be delayed. With people living longer, healthier lives, it’s certainly merging, from 40s and 50s into one’s 60s and beyond. Maybe in the future more people in their 60s will still be caring for children and their parents, or be changing jobs, or getting additional education – things that they didn’t do earlier.

Between ‘preventative’ Botox, the ‘forever 35’ facelift and drugs like Ozempic, it increasingly feels as though visible signs of ageing, at least in women, are being erased. What’s your view?

Certainly, in western cultures, people don’t want to be old. We now have the knowledge and products to be able to slow ageing. I think it is unfortunate, this negative view of ageing.

At the same time, wanting to look and feel young is not necessarily a bad thing. What we find is that subjective age – how young you feel – is as important or even more important in terms of predicting health than your chronological age. We can’t really tell much from chronological age without digging deeper and looking at biology, cellular changes and chronic conditions, but what people tell you about how old they feel reflects a lot of what’s going on inside.

Of course there are many different ways to look and feel young, some more radical than others. I don’t know the negatives of engaging in these treatments, so I don’t want to advocate doing them, but I think whatever makes you feel young is a good thing, in a way.

One negative perception of midlife is that your course and identity are fixed. How much power do we have to change in middle age?

We actually see positive changes in personality, on average, as people get older. They become more agreeable, more conscientious and less neurotic – so less anxious – and less depressed.

Personality is just your behaviour, thoughts and feelings, and you can change those things. I’m not saying it’s always easy, if you’ve been a certain way for 30 or 40 years, but personality and identity typically stabilise in the 50s. People are still able to make changes in their 40s.

If you feel you’re socially isolated and want to become more outgoing, you can actually change your behaviour and become more extroverted, just by engaging in more conversations and going to more social events. You can become more conscientious by getting to meetings on time, things like that.

What about our physical health, when so much is determined earlier in life and by our genes?

You can’t stop ageing, but you may be able to slow it down. Things like bone loss, muscle weakness and decline in lung functioning are very slow, gradual processes: people typically don’t notice them in midlife, but if you don’t start doing something about them then, you will feel more effects later on, and things can really go downhill. That’s one of the points I really want to hit home: your health in midlife is really important, not only for that current period, but also the long term.

The good news is, there’s a lot you can do. Genetics is responsible for between 25-50% of longevity and health, but even if it’s 50%, you still have a lot of control. Lifestyle does make a really big difference, and blood pressure, glucose levels, cholesterol and weight are modifiable.

We can see that an investment in your health in midlife pays big dividends later on, so it’s important to get regular checkups, monitor these physical indicators and try to improve them. The earlier you start with those typical healthy lifestyle behaviours, the better, but it’s never too late. Whenever you stop smoking, for example, it gives you added life.

How else can you improve your chances of a positive experience of middle age?

Mindset makes such a difference. If you feel like it’s all downhill from here, it’s kind of a self-fulfilling prophecy, so being optimistic, and looking forward to the future, is really very important. If you think you have the ability to bring about desirable outcomes, you’re going to be more likely to engage in these health-promoting behaviours. If you think there’s nothing you can do, why bother, right?

A lot of people have this older mindset: they think they’re old, so they act old. In fact, it’s quite possible that, at 40 or 50, you have as much time left as you’ve already lived. Of course not everybody makes it past midlife, but why go with that expectation? The odds are, statistically speaking, we have a lot of time left. I think that’s very positively motivating: “I don’t want to waste the rest of my life. What do I want to do and am I going to do it?” If you think about midlife as an opportunity, it opens up possibilities for growth, wellbeing and long-term health.

So how can we keep feeling young?

Feeling that you have purpose and meaning in life, that you’re making a difference – that keeps people feeling young. Mentoring others, too. Especially as you get into your later 40s and 50s, you have a lot to offer in terms of knowledge and experience.

Being around younger people can also be really invigorating, and not just because you keep up with current trends. My lab has people of different ages, and we all contribute different things, based on our experience and knowledge: the whole is greater than the sum of the parts.

• Primetime: A New Vision for Midlife by Margie Lachman, PhD is published by Simon Element on 9th June