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Is happiness in our genes?

Claire Haworth speaks to Gareth Jenkins as part of the What Makes Us Happy series, following conversations with Libby Burton, Sarah Stewart-Brown and Eugenio Proto and Andrew Oswald.

Twins two women smiling and laughing

Professor Claire HaworthClaire Haworth joined the University of Warwick’s Department of Psychology in 2013, and is now Reader in Behavioural Genetics. Since 2011, Claire has led the Twins Wellbeing Intervention Study (TWIST). The British Academy-funded research investigated the influence of our environment and genetics on our state of wellbeing and methods to improve our levels of happiness. Claire spoke to Gareth Jenkins about TWIST and her interest in the science of happiness.

Q) What is it like to research ‘happiness’?
People can be a bit funny about research into ‘happiness’ – they think it’s all Pollyanna-ish and that we want everyone to be happy all the time, but we don’t. Happiness would be an inappropriate emotional reaction to every situation.

Q) If we’re not looking at making everyone happy, what should we be looking to do?
We need to understand what being mentally healthy means. It seems odd that we don’t know exactly what that is, given that we’re developing treatments to help people who are having mental health problems. We want to help people get better, but to do that we need to understand what being mentally healthy looks like, and how we can promote mental health.

Is happiness in our genes video YouTube linkQ) How does the Twins Wellbeing Intervention Study (TWIST) fit into that?
TWIST was an unusual study. I wanted to combine genetic methodology with intervention science. When people undertake an intervention – such as when you’re asked to eat five pieces of fruit and veg a day – some will respond better than others. One way to understand why is through genetically sensitive methods that can tell us about the roles of nature (genes) and nurture (environments) in creating these differences between people. I used a twin methodology with TWIST and brought in two interventions for wellbeing. The study was conducted online over a ten-week period, and 750 teenage twins took part.

Q) What were the interventions?
We asked the twins to perform three acts of kindness and report back on what they did and we also asked them to write three letters of gratitude to three different people. They’re some of the most well-validated wellbeing interventions in psychology. The acts of kindness were to be performed in one day. This is because doing it across a week is too easy; it’s almost effortless to hold a door open once a day on three different days. But making someone do something like that all in one day changes their perspective; they spend the entire day looking for opportunities to perform acts of kindness.

Q) What constitutes an act of kindness?
It’s better if you work that out for yourself. Deciding what will be helpful to others, and who you should write a letter of gratitude to, is all part of the intervention.

Q) Did the interventions work?
They did. We improved wellbeing for the group and there are also really interesting genetic findings to the study. It’s important to note though, a wellbeing study won’t make everyone happier. We had a full range of results in our study with some people experiencing greater boosts to their wellbeing than others. We hope that by understanding why some people got more benefits from the intervention than others, we can start thinking about personalising interventions.

A new frontier for interventions will not be comparing an intervention with no intervention, but comparing various combinations of interventions to see which work best for each individual.

Q) So are some people born happier than others? Is happiness genetic?
For complex traits there are always going to be many, many genes involved, perhaps thousands of DNA variations. So there isn’t a gene for happiness, but there are lots of genes and these interact with our environmental experiences to influence our levels of wellbeing. Genetic influences aren’t deterministic. So it’s possible to carry the genetic variations that make you more or less likely to be happy but aspects of your environments could override these influences so that they are never shown.

Overall, some people find it easier to be happy than others, and part of that is due to their genes. Some people may find it easier to increase their happiness, whereas others may need to invest more effort into it. But it is not impossible and the key is finding what works for each individual. Twin studies, like ours, go beyond ‘is it genetic?’ though, they tell us more about the environment than they tell us about genes.

Q) How so?
They tell us about environments that are shared and that make the twins similar to each other and they tell us about what we call non-shared or unique environments. So, for identical twins, the only thing that makes them different from one another are these unique environmental experiences and exposures. We can estimate how valuable these unique experiences are, and you can start to think about what they might be in real life; so it might be having different friends, it might be having a different teacher or getting different reactions to your acts of kindness.

There are lots of ways in which there are experiences they don’t share even though they grow up together. What we found in the study is that it’s these unique non-shared environmental experiences that are the most important environmental experiences. So it’s not something that seems to be family-wide – an environment that influences both of them – and it’s not the general family ethos towards gratitude or kindness; it’s something really unique to each individual. These unique, non-shared experiences were what explained the change in wellbeing in response to the intervention.

Q) Did the twins enjoy the study?
We got a lot of positive feedback from the teenagers about this study. Some of the feedback that we got was that they’d never had the chance to think about writing letters of gratitude or regularly performing acts of kindness before. The twins in the study were all teenagers; the world’s whizzing by them and they’ve never really stopped to think about the teacher who changed their life or that they were grateful to their parents for supporting them and allowing them to explore their dreams.

Q) Any challenges?
One particular challenge was that no one’s done a wellbeing intervention in twins before and that life might just be different growing up as a twin. I have a twin brother; so I grew up with someone that I always knew in each school year; we went to the same school and we were often in the same classes. So it is slightly different. We had to think about how that might impact the results.

Q) Do you think it has?
We’ll look at whether they always helped their twin, but from my initial reading of the acts of kindness, I think it’s going to be a no. In fact, the main people who appeared in the acts of kindness and in the letters of gratitude were parents.

Q) Who else was involved in the study?
There were around 750 twins in our study and these all came from the larger Twins Early Development Study (TEDS). TEDS has around 10,000 active families from across the UK taking part in research. When I started doing this I was quite new to the field of wellbeing and intervention, my background is in behavioural genetics and trying to understand the roles of nature and nurture, but I saw the benefit of trying to combine it with intervention science.

One of the best things I did was getting in touch with an internationally renowned group based at the University of California Riverside. The Positive Psychology Laboratory is led by Professor Sonja Lyubomirsky. Sonja’s done a lot of work around the methodologies for wellbeing interventions, such as performing all the acts of kindness in one day.

Q) Have you published your results?
We’ve just written the first paper from the study and we’ll submit it for publication soon. For the first paper we’ve asked broad questions about whether the intervention increased wellbeing, and how important genes and environments were for wellbeing across the study. Now we’re trying to understand who the intervention worked best for; who got the biggest benefits to their wellbeing – was there something special about the kinds of activities they chose to do?

Q) What’s the future of improving our wellbeing?
Showing no symptoms of mental illness is not necessarily the same as being happy and having a flourishing life. One of the theories I have is that mental health therapies might be more effective, in the long term, if we treat the symptoms of mental illness – bringing someone up to ‘zero’ – before introducing a different wellbeing intervention that helps them feel better. Wellbeing interventions are not a replacement for clinical therapies, but they may be useful as a second stage to promote wellbeing and help people to remain mentally healthy.

Q) A bit like how a football player would see the club doctor and the physiotherapist after an injury?
Exactly. Whilst everything could heal after an injury, a footballer might not play as well as they could before but they want to get back to peak performance or as close to it. The ‘physio’ comes in at this stage. A two-stage intervention could work really well. What we want to do is give people a bit of a buffer. I think this could be revolutionary in terms of public health.

More articles in this series:

Can we measure happiness? Sarah Stewart Brown, Warwick Medical School
There's something about the Danish Andrew Oswald and Eugenio Proto, Department of Economics
Is happiness homemade? Libby Burton, WMS, School of Engineering

Image by Paul Daly, University of Warwick