Reflecting on what one is thankful for lowers aggression, according to a new study by the University of Kentucky. The research suggests gratitude, or gratefulness (they mean the same thing), should be expressed on more than just a single day of the year, Deseret News reported.

Study researchers determined the physical benefits of gratitude through a multiple stage experiment.

First, just over 150 UK undergraduate students had to write an essay about an event that caused them anger. Second, (depending on which group they were assigned) they had to either list things they liked to do with someone for which they felt compassion or list reasons why they were grateful for that particular person. The initial essays were then reviewed and returned with either positive or negative remarks. The third stage was a game between students and their evaluators -- with the winners earning the right to blast their opponent with a level of white noise raised to their choosing, according to the Deseret News.

Those who received negative essay comments blasted the loudest and at the highest levels, but only if they were in the essay group that wrote about things they liked to do with their person of compassion. Students who were primed for gratitude showed the least aggression during the noise game, regardless of whether they received negative or positive essay comments, Deseret News reported.

The paper, titled, "A Grateful Heart is a Nonviolent Heart: Cross-Sectional, Experience Sampling, Longitudinal, and Experimental Evidence," (actually published in September) concluded that gratitude leads to non-aggressive behavior, according to uky.edu.

"Take a step back, and look at what you've got," said UK Professor Nathan DeWall, who led the study. "Don't spend every waking moment being grateful, but one time a week definitely increases your well-being over time. And if you get bad news - you're given a shot that protects you."