Flexible working is considered good practice – and in England, most workers have the right to apply to work flexibly after they’ve been in their job six months. But what do we know about the benefits? A new study by Tarani Chandola and colleagues used biological measures to look at differences in stress markers among workers with reduced hours and those without.

In recent years many employees have been able to alter their work patterns to fit in with childcare and other responsibilities. Typically, this can mean working part-time, job-sharing, only working during school term-times or working from home some of the time.

It’s assumed this should help to relieve stress. But until now, we didn’t know whether this was necessarily the case. After all, there could be down-sides – for example working at home can mean a blurring of the boundaries between work and family time, part-time working can be a barrier to promotion and job-sharing can bring its own tensions.

Until recently we had to rely on workers’ own reports of how they felt in order to judge this interplay between work, family life and stress. But now a number of social surveys have begun collecting samples which allow us to measure biological changes which can indicate stress, too.

This is known as ‘allostatic load’ – when we’re repeatedly subjected to stress or trauma, this can lead to chronically heightened levels of stress hormones. And that is associated with all sorts of long-term health problems, such as heart disease, type-2 diabetes and depression.

We were able to use data from participants in the Understanding Society study, which began in 2009 and which follows more than 60,000 adults in 40,000 households. As well as responding to detailed questionnaires, many of them have been visited by nurses who have taken physical measurements and blood samples.

Blood-based markers

As well as blood-based markers such as insulin growth factor 1 and cholesterol, their pulse rate, blood pressure and waist-to height ratio were also measured.

After taking out those who weren’t employed, who didn’t have the nurse visits or for whom some measurements were missing, we had a sample of a little over 6,000 people.

All those people had been asked whether flexible working arrangements were available at their workplace, how many hours they worked and whether they were the primary carer for their children.

We categorised working hours into three groups, with different levels for men and women because they tend to have very different working patterns. So women were grouped into those working less than 24 hours per week, more than 25 hours and more than 37 hours; while men were grouped into those working less than 37 hours, 37-40 hours and more than 40 hours.

Unsurprisingly, we found more women than men had made use of flexible working  arrangements – almost no men in our sample were the main carers for two or more children.

Chronic stress

There were particularly high levels of biological chronic stress markers among women with childcare responsibilities who worked more than 37 hours per week. Those with similar childcare responsibilities but working fewer than 25 hours per week didn’t have any measurable effect on their stress levels.

Both men and women who had access to, and made use of, reduced-hours flexible working had lower levels of biological stress markers than those who didn’t have flexible working.

We found these types of reduced-hours arrangement were more common among those in lower-paid occupations, especially among men, and among older workers of both genders.

Other types of flexible working arrangements, such as working from home, were more common among those from more advantaged social groups. But we didn’t find any association between these types of working and lowered levels of stress.

So, what has our study told us? We’ve learned a good deal about the complex relationships between social and biological factors in our lives. And, crucially for policymakers, we can see that it’s particularly important for women with childcare responsibilities to be able to access shorter working hours when they need to. For employers, this isn’t just a matter of logistics and of ensuring a stable and happy workforce – it’s also a major factor in ensuring that workers live longer and healthier lives.

Are Flexible Work Arrangements Associated with Lower Levels of Chronic Stress-Related Biomarkers? A Study of 6025 Employees in the UK Household Longitudinal Study, is research by Tarani Chandola (University of Manchester and UCL), Cara Booker, Meena Kumari and Michaela Benzeval (University of Essex) and is published in Sociology.