Kimberly Schonert-Reichl, a professor in University of British Columbia, and co-author Kristin Layous, of the University of California, Riverside, said increasing peer acceptance is key to preventing bullying.
Four hundred students from Vancouver elementary schools ages 9-11 were asked to report on their happiness and to identify which classmates they would like to work with on school activities.
Half of the students were asked by teachers to perform acts of kindness such as sharing their lunch or giving their mom a hug when she felt stressed -- and half were asked to keep track of pleasant places they visited such as the playground or a grandparent's house.
After four weeks, the students again reported on their happiness and identified classmates they would like to work with. Both groups said they were happier, children who had performed acts of kindness selected higher numbers of classmates to work with on school activities.
"We show that kindness has some real benefits for the personal happiness of children but also for the classroom community," Schonert-Reichl said in a statement.
Bullying tends to increase in Grades 4 and 5. By simply asking students to think about how they can act kindly to those around them, "teachers can create a sense of connectedness in the classroom and reduce the risk of bullying," the researchers said.
The findings were published in the journal PLOS ONE.