Who said "Being grateful makes you happier."?

This quote is attributed to Kenny McCormick.

Being grateful makes you happier. - Kenny McCormick

"Being grateful makes you happier."

Kenny McCormick Gratitude

"Mmph mmph mrmph!"

"I'm not fat, I'm just big boned"

"Dude, we're in third grade"

"This is so cool"

"Gratitude makes life richer."

"A grateful heart is a happy heart."

"Respect those who came before us."

"Life's greatest treasures are the people we love"