Smiling is a natural response to happiness - but could happiness be a natural response to smiling?
According to a new study, smiling can trick your brain into feeling happy.
A study published in Psychological Science looked into whether manipulating facial expressions could have an influence on cardiovascular responses to stress.
Participants held chopsticks in their mouths to use the same muscles needed for an authentic smile.
Half of the volunteers were told to smile, while the other half were told to keep a neutral expression.
Even while doing stressful activities, people who had a smile on their faces had lower heart rates.
But even those who were told not to smile but had the chopsticks in their mouths reported coming out of the task feeling more content than the control group.