By comparing identical twins, researchers uncover why working for yourself may come with hidden stress costs, but why long hours matter more than job variety.
Study: Does self-employment increase stress? A co-twin control analysis of Finnish and US twins. Image credit: gpointstudio/Shutterstock.com
A recent study of identical twins from Finland and the United States finds that self-employment is associated with higher levels of perceived and physiological stress than non-self-employment. The study is published in the Journal of Business Venturing.
Mixed evidence clouds whether self-employment reduces or raises stress
Entrepreneurship gives people a sense of independence and freedom to work on projects they are passionate about. These factors are often thought to improve mental health and reduce stress among entrepreneurs and are frequently linked to high job satisfaction and autonomy. However, entrepreneurs often experience several stressful conditions, including long working hours, which may counteract these potential benefits and increase their stress levels.
Previous studies investigating the association between self-employment and stress have produced mixed results, which may be due to limitations in study design for disentangling the effects of a person's stress tolerance from the stressors of self-employment.
People who are more resistant to stress may be more likely to be entrepreneurs, given the known risk factors and long working hours associated with self-employment. Alternatively, people who struggle to handle the stress of regular employment may be drawn to self-employment, believing that working on their own terms would be a much better option. All these predispositions can potentially mask the actual effect of self-employment on stress.
Given these discrepancies in the existing evidence, researchers from Bayes Business School, UK, Warwick Business School, UK, and the University of Notre Dame, USA, conducted two independent twin studies to investigate the impact of self-employment on stress, controlling for genetic and shared environmental factors.
Identical twin comparisons isolate stress effects of self-employment
The research team conducted two separate studies on identical twins. The first study included 4164 twins from Finland whose stress levels were assessed using the Subjective Stress Scale. The second study included 561 twins from the United States, whose stress levels were assessed by measuring salivary cortisol levels.
Among enrolled twin pairs, one was self-employed, and the other was regularly employed in organizational roles or other non-self-employed work. Being identical twins, they share 100 percent genetic similarity and grew up in similar environmental conditions, enabling researchers to better isolate the association between self-employment and stress from genetic and shared environmental influences.
Self-employed twins report higher stress and cortisol levels
The findings of the first study revealed a significant positive association between self-employment and self-reported stress. Specifically, self-employed individuals reported 24 percent higher stress than their identical twins who were not self-employed.
The findings of the second study revealed a significant positive association between self-employment and salivary cortisol level later in the day, indicating that self-employed individuals experience higher physiological stress after work than their identical twins who were not self-employed. On average, cortisol levels were 53 percent higher in saliva samples collected in the evening from self-employed individuals than in their twins.
Regarding potential mediators, both studies revealed that long working hours significantly contribute to the observed impact of self-employment on stress. However, the study did not find any significant stress-reducing effect of job variety, which is often associated with self-employment.
These findings indicate that the strong influence of long working hours may outweigh or offset any beneficial effects of a high degree of job variety in self-employment, at least with respect to stress outcomes, even though job variety may support other aspects of well-being.
A call for healthier, more sustainable self-employment models
This twin study reveals that self-employment is associated with significantly higher perceived and physiological stress, independent of genetic and shared environmental factors. This heightened stress is associated with high job demands and long working hours, which are common in self-employment.
The self-employed nature of work appears to be associated with changes in stress hormone levels, which may impair recovery from stress rather than directly reducing performance. The increased cortisol levels observed in self-employed individuals in the evening indicate a reduced ability to physiologically unwind after work, which is a recognized marker of chronic stress rather than a direct measure of illness or reduced productivity.
The study used the co-twin control methodology, which uses identical twins to control for selection effects arising from genetics and environmental experiences. This novel approach provides empirical evidence that the association between self-employment and stress is robust to genetic and shared environmental influences.
The findings also highlight the need to develop sustainable models of entrepreneurship that support a healthy work-life balance and reduce administrative and workload pressures, thereby improving the mental health and well-being of this economically important yet health-vulnerable group, alongside broader policy and organizational support mechanisms.
Overall, these findings suggest that individuals planning to become entrepreneurs should be aware of the potential stress they may encounter at work, identify their stress tolerance levels, plan to cope with stress, and develop personal stress-management techniques, such as self-help tools or psychological counseling.
Several studies have linked chronic stress to adverse mental and physical health outcomes. It is a major cause of work burnout. However, the research team stated that the increased stress among self-employed individuals may not always be harmful; some stressors may also have a positive effect if they remain within an acceptable range.
Future studies should analyze different types of stress stimuli, such as challenge and hindrance stressors, to better understand the role of stress in the entrepreneurial process, particularly across different forms of entrepreneurship beyond self-employment.
Download your PDF copy now!
Neighborhood disadvantage accelerates biological aging through emotional distress