As people spend more and more time in the workplace, it’s natural for co-workers to develop close bonds — what’s often referred to as a “workplace spouse” or an “office wife.”

But when it comes to pay raises, promotions and other measures of career success, it’s the husband or wife at home who may be exerting a bigger influence on workplace performance, suggests new research from Washington University in St. Louis.

“Our study shows that it is not only your own personality that influences the experiences that lead to greater occupational success, but that your spouse’s personality matters too,” said Joshua Jackson, PhD, assistant professor of psychology in Arts & Sciences and lead author of the study.

Although we marry “for better for worse, for richer for poorer,” this study is among the first to demonstrate that the personality traits of the spouse we choose may play a role in determining whether our chosen career makes us richer or poorer.

“The experiences responsible for this association are not likely isolated events where the spouse convinces you to ask for a raise or promotion,” Jackson said. “Instead, a spouse’s personality influences many daily factors that sum up and accumulate across time to afford one the many actions necessary to receive a promotion or a raise.”

Forthcoming in the journal Psychological Science, the findings are based on a five-year study of nearly 5,000 married people ranging in age from 19 to 89, with both spouses working in about 75 percent of the sample.

Jackson and co-author Brittany Solomon, a graduate student in psychology at Washington University, analyzed data on study participants who took a series of psychological tests to assess their scores on five broad measures of personality — openness, extraversion, agreeableness, neuroticism and conscientiousness.

In an effort to gauge whether these spousal personality traits might be seeping into the workplace, they tracked the on-the-job performance of working spouses using annual surveys designed to measure occupational success — self-reported opinions on job satisfaction, salary increases and the likelihood of being promoted.

Workers who scored highest on measures of occupational success tended to have a spouse with a personality that scored high for conscientiousness, and this was true whether or not both spouses worked and regardless of whether the working spouse was male or female, the study found.

Jackson and Solomon also tested several theories for how a spouse’s personality traits, especially conscientiousness, might influence their partner’s performance in the workplace. Their findings suggest that having a conscientious spouse contributes to workplace success in three ways.

First, through a process known as outsourcing, the working spouse may come to rely on his or her partner to handle more of the day-to-day household chores, such as paying bills, buying groceries and raising children. Workers also may be likely to emulate some of the good habits of their conscientious spouses, bringing traits such as diligence and reliability to bear on their own workplace challenges. Finally, having a spouse that keeps your personal life running smoothly may simply reduce stress and make it easier to maintain a productive work-life balance.

While previous research with romantic partners has shown that a bad experience in one social context can bleed over into another (a bad day at work can lead to a grumpy spouse and a tense night at home, for example), the Jackson/Solomon study goes beyond this to suggest that these sort of patterns exist day-in and day-out, exerting a subtle, but important influence on our performance in environments far removed from our home lives and our spouses.

The findings, they suggest, also have interesting implications for how we go about choosing romantic partners. While previous research suggests that people seeking potential mates tend to look for partners who score high on agreeableness and low on narcissism, this study suggests that people with ambitious career goals may be better served to seek supportive partners with highly conscientious personalities.

“This is another example where personality traits are found to predict broad outcomes like health status or occupational success, as in this study,” Jackson said. “What is unique to this study is that your spouse’s personality has an influence on such important life experiences.”