Which comes first: happiness or success?

It’s a chicken-and-the egg question. Which comes first: happiness or success? Does success make you happy, or does happiness make you more likely to succeed?

That’s the question Paul Lester, associate professor of management at the Naval Postgraduate School; Martin Seligman, director of the University of Pennsylvania’s Positive Psychology Center; and the late Ed Diener, an influential American psychologist, attempted to answer.

For five years, the researchers followed nearly 1 million employees of the U.S. Department of Defense across all job functions. They measured their relative happiness and optimism with questions from the Positive and Negative Affect Schedule and the Life Orientation Test (tools used by the military to gauge well-being) and compared them to the number of awards an employee earned. Their findings, “Happy Soldiers Are Highest Performers,” are published in the MIT Sloan Management Review.

“When leadership makes a decision to put you in for an award, there’s a pretty rigorous process to go through before it’s actually given to somebody,” Lester says. “Of approximately a million employees, just 12.6% received an award. These aren’t participation awards; receiving an award is rare.”

The Happiness Impact

Those with the highest positive well-being affects had almost four times the number of award recognitions as those in the group with the lowest well-being scores. The researchers also found that while negative feelings like sadness and anger predicted fewer awards, having low levels of positive emotions did also.

“We were able to focus on the impact of happiness as a predictor of performance,” Lester says. “High negative feelings interfere with good performance, and high optimism predicts a greater odds of superior work performance.”

The bottom line of the study is that you don’t have to have success to be happy and you don’t have to be happy to find success. People who could be considered unhappy compared to their peers still earned awards for performance, but they earned them at a lower rate than people who were happy overall.

“Happiness could give you a greater chance of being successful,” Lester says. “Skills, knowledge, ability—all of that matters greatly. And we’re not saying that that happiness is more important than all of those other things. We are showing that happiness is a measurable predictor of performance.”

What This Means to You

The study findings have applications in the civilian world. The Defense Department is the single largest employer in the world, with about 190 different types of jobs, from truck drivers and pilots to doctors and lawyers. The researchers were able to look across a wide swath of fields and demographics, race, genders, tenure, and job characteristics.

“That’s what made the study special, not only its depth but its breadth,” Lester says.

Since happiness can be a precursor to success, Lester and his fellow researchers encourage organizations to focus on employee well-being and optimism. “Happiness matters and should be measured,” he says. “In a sense, it’s a proxy for the health of the organization itself. There’s value in measuring and developing it.”

Instead of relying on management intuition, start by using assessment tools with current employees as well as prospective hires to gauge well-being, optimism, and overall happiness. Many organizations already use behavioral screening to evaluate job candidates. If it doesn’t include questions about happiness and optimism, it should be updated with this element.

Organizations should also pay attention to toxic leadership and employees, who can cause unhappiness in others, impacting performance and leading to higher attrition. Training leaders to better manage employees can help, although more severe measures, such as firing, may be necessary to protect the overall mental health of the team.

Another step to take is to develop happiness in your workforce. Lester and the researchers suggest implementing simple exercises, such as encouraging employees to make testimonies of gratitude to someone who changed their life for the better. Or have employees write down three things that went well each day for a week. Previous research by Seligman has shown that these positive interventions can increase happiness and decrease depressive symptoms.

Finally, Lester says leaders should model a focus on well-being. “If leaders want to improve employee happiness, they must model that which is taught so that it becomes integral to the organization’s lexicon and culture,” he says. “We learn best from watching other people. The big takeaway is that the happiness of your employees matters. Yes, objective measures of performance matter to the organization. That’s why your organization exists for whatever reason. But in the end, a gauge of how well your company is doing is assessing the overall happiness of your employees.”