A study of more than 400 Vancouver students aged nine to 11 split the children into two random groups. One was asked to visit three favourite places each week for a month, the other group to perform three kind gestures a week over the same period. That included sharing their lunch or carrying shopping.

Among the places the children chose to visit were the shopping centre and their grandparent's house.

Published in the journal Plos One this week, the results showed that after a month of monitoring, the children who performed kind gestures were far happier than their counterparts.

And while both groups had an increased sense of wellbeing, only the group that performed kind acts experienced greater acceptance by their peers.

This was measured by student surveys, which asked the children to nominate which of their classmates they would like to do a school activity with. The peer nomination showed the students who performed kind acts gained an average of 1.5 friends.

The results from University of British Columbia and University of California researchers back up earlier studies and have implications for teachers.

The lead author, Kristin Layous, from the University of California's department of psychology, said educators would do well to introduce classroom activities that promote and provide the opportunity for students to help each other.

"The findings suggest that a simple and relatively brief prosocial activity can increase liking among classmates,'' she said.

''Given the relationship between peer acceptance and many social and academic outcomes, we think these findings have important implications for the classroom."

Promoting kindness could increase connectedness and thus reduce bullying, the study concluded.