It's easy to underestimate the effect your gratitude can have on those you work with. As a leader, you're likely letting people know how they can improve. But there's one thing you may have overlooked that can have a powerful effect on workplace happiness: a simple "thank you" message.

Now, this isn't the same as shooting off a last-minute "Thanks, good work!" email (which, let's face it, will end up lost in some endless thread). I'm talking about writing out a brief, specific letter of appreciation which can significantly help boost morale and employee well being.

A missed opportunity

While some leaders may worry that gratitude makes them seem weak, one survey of 2,000 Americans revealed that 93 percent of those polled agreed that grateful bosses were more likely to be successful.

Yet, the data points to another interesting finding: people were least likely to express gratitude in workplaces-- despite wishing to be thanked more often themselves at work.

So what prevents leaders from doing something that is so seemingly simple?

"People think it's not that big a deal," explains social psychologist, Amit Kumar, the lead author of a recent study that looks at how people tend to undervalue the effects of showing their gratitude. "What was interesting to me is that even though it's something that's well-known, people still don't express gratitude all that often."

In his findings, Kumar discovered that many believe that expressing thanks will be awkward, or that the other person will be offended by receiving an array of compliments. Yet his research showed that people underrated the positive effects their letters had on the recipient.

"We found that expressers may worry inordinately about how they are expressing gratitude -- their ability to articulate the words 'just right' -- whereas recipients are focused more on warmth and positive intent," the study authors wrote.

Don't worry about competence

As educationist and suffragist, Margaret Cousins wisely noted: "Appreciation can change a day, even change a life. Your willingness to put it into words is all that is necessary."

Writing up an earnest thank you letter doesn't require "the perfect words." Leaders should try to abide by these two rules of thumb: keep your message warm and sincere. In other words, worry less about eloquence and more about conveying genuine appreciation. 

"When we're thinking about ourselves, we tend to think about how competent we are -- are we going to be articulate in how we're expressing gratitude," says Kumar. But this may cause an unwarranted barrier for leaders to practice giving thanks on a regular basis.

So how are some ways to show your gratitude? 

  • Be specific: generic "thank you"s are quickly forgotten, but letting an employee know their presentation was thoughtfully executed or that they delivered an excellent sales pitch sends a message that you are paying attention and appreciate their efforts.

  • Give honest appreciation: avoid giving a false compliment just to show your sense of gratitude. Really notice the areas where they are making a positive impact and mention them.

Innumerable benefits

Other studies have shown that grateful feelings have several beneficial effects: They enable people to savor positive experiences, cope with stressful circumstances, and strengthen social relationships. 

Acknowledging when your employees have a positive impact shows you value them, but according to Kumar's research, the rewards of expressing thanks aren't limited to the recipient. Writing out your gratefulness will make you happier as well.

 "What we saw is that it only takes a couple minutes to compose letters like these -- thoughtful and sincere ones," says Kumar. "It comes at little cost, but the benefits are larger than people expect." Indeed, counting one's blessings can increase your own positive emotions, well-being, and health. 

The most effective leaders understand that gratitude is a two-way street that ultimately influences their overall workplace culture. 

Give thanks continuously

In an interview for The Wall Street Journal, acclaimed psychologist and author, Adam Grant, emphasizes that "a sense of appreciation is the single most sustainable motivator at work."

He explains that while other extrinsic motivators can stop having meaning (e.g. spending one's bonus or getting a raise, which gets taken for granted) "the sense that other people appreciate what you do sticks with you."

The bottom line is that you should take inventory of the people working hard to foster a positive work environment and then commit to appreciating them in writing. Sharing your gratitude won't take up more than a few minutes of your day, but it offers an enduring, powerful way to let others feel seen.