I’ll always remember being in a restaurant in Portugal with my father many years ago.  We were enjoying dinner with twenty or so friends around a large table, and a random remark made by one of these friends triggered his laughter.  It started out as a light chuckle and quickly developed into an all consuming belly laugh. At first only a few smiles appeared on our friend’s lips – as most of them had not been not part of the original conversation – but soon the entire table (and then unrelated people in the restaurant!) found themselves laughing wholeheartedly.  No one was really sure as to the cause of the amusement, but they were all entranced by my father’s contagious laughter.

While laughter or smiles may just show a glimpse of happiness, research shows that happiness can be as contagious as a common cold! According to a study under Harvard MD and sociologist, Nicholas Christakis, and James Fowler, professor of political science at UC San Diego, if your friend is happy then your chances of being happy increase by 15%; if your friend’s friend is happy, your chance of being happy increases by 10%, and if it’s a friend of a friend of a friend then your chance increases by 6%!

Check out this visual that represents 353 students who are part of a social network in Facebook:

Each line indicates that these individuals were linked in a Facebook photo. Yellow nodes represent students who are smiling in their photo and who were surrounded by smiling people in their network. Blue nodes were frowning faces and greenish nodes represent a mix of smiles and non-smiles. What is interesting is how the same-colored nodes tend to be clustered together….Moreover, students who were smiling were much more likely to have a greater network of friends than their non-smiling peers.

Christakis was able to replicate this phenomenon when he charted the networks and relationships of friends, spouses and siblings.

For organizations this is further ‘proof’ that investing in individual employee’s well-being will influence the well-being and consequently the effectiveness of the entire organization.

So, what are you as a leader doing that allows your team to thrive and positively affect others around them?