University of Essex study asks: ‘Do partners influence each other’s health?’

Dr Apostolos Davillas, of the University of Essex. Picture: University of Essex. (Image: Archant)

In fact, it seems that the opposite could actually be true - we’re driven to select like-minded partners.

Research published in the US last year studied a variety of pairs, both those who had just met and long term couples or friends, and found that people who had known each other longer were no more alike than the more recently acquainted, suggesting that similarity is an important factor for striking up a successful relationship from the very start and contradicting the idea that couples can change each other over time.

And yet more research found it’s not just that we’re attracted to those with a similar world view to ourselves but perhaps also to those with similar looks.

A 2010 report published in Personality and Social Psychology Bulletin found that not only are we attracted to people who resemble family members, but when those who participated in the study were shown photos of strangers and photos of themselves morphed with photos of those same strangers, they were more attracted to the photos in which their faces had been morphed.

Now researchers in East Anglia have taken the theory even further, suggesting we are attracted to those with whom we share a similar ‘health status’ and that couples influence each other’s health, meaning if one person is suffering from a particular illness their partner might be at risk of developing it too.

The new study, co-authored by Dr Apostolos Davillas at the University of Essex’s Institute for Social and Economic Research, suggests that because of this, it’s important to target health policies at couples, rather than individuals.

Using data from Understanding Society, an academic study capturing information every year about the social and economic circumstances and attitudes of people living in the UK, Dr Davillas and Professor Stephen Pudney, from the University of Sheffield, aimed to identify whether health similarities between couples were down to people seeking partners similar to themselves or because of shared lifestyle and environmental factors.

“It’s often assumed that partners who live together influence each other’s lifestyle choices - for example, physical activity, eating habits and so on - but relevant research has also suggested people often seek partners who have the same socio-economic characteristics as them (something known as homogamy), probably implying similar health statuses,” says Dr Davillas.

Analysing health information relating to more than 12,000 couples, the researchers found that “homogamous partner selection and casual shared lifestyle” make roughly equal contributions to the consistency of health states seen in couples.

“These findings are relevant to public policy and the capacity of couples to absorb adverse shocks,” says Dr Davillas. “Even if health selection occurs at the time of partnership formation (homogamy), a causal effect of the shared environment is necessary for health concordance to persist or increase through time.

“We find that shared lifestyle factors and homogamous partner selection make roughly equal contributions to the concordance of health states in couples.

“This matters for policy because persistent concordance may result in wider health inequalities across couples and any tendency for disability and morbidity to become more concentrated within couples also affects the social cost of disease.

“Separating homogamy from causal concordance may be also relevant for public health prevention programmes. Although homogamous health selection is largely immune to policy, evidence on causal effects of shared environment and lifestyle may provide a basis for screening programmes and other interventions that exploit information on the health of one partner to identify elevated risks for the other partner.”