Personality Traits as Moderators of the Effects of Working Hours on Mental Health

Although theoretical models of job stress have suggested that various worker characteristics and workplace conditions may moderate the effects of occupational burdens on workers' health, few studies have investigated the impact of working hours on mental health while considering individual and workplace characteristics. In this paper, we explore the impact of personality traits on the relationship between job burdens associated with long working hours and workers' mental health and evaluate these impacts over several measurement periods. Our findings are as follows. First, long working hours have more negative effects over long periods of time than over short periods. Second, people who are less extroverted and less open are more susceptible to the mental health effects associated with long overtime hours. These results suggest that company HR personnel and managers should consider the needs of employees who are less extroverted and less open, particularly if they consistently have long working hours.