Contentment: image via fazdleeisa.wordpress.com Researchers at Harvard University and the Massachusetts Institute of Technology (MIT) have, for the first time, scientifically measured the spread of emotions on the same scale that measures disease transmission. Not only have they been successful at evaluating the spread of long term emotional states, but they actually quantify the spread of contentment versus the spread of discontentment.
Epidemiologists know that infectious diseases spread through social networks. Social scientists know that certain attitudes, ideas, and behaviors influence members of social networks and the more members associate with their peers in those networks, the greater the likelihood of that influence. And even happiness has been correlated between individuals such as family and friends.
But the Harvard/MIT team, led by Dr. Alison L. Hill, wanted to see if the correlations of happiness and discontent would hold up under mathematical scrutiny. The classical model of disease infection, measured by the SIS (susceptible–infected–susceptible) was extended by the researchers to include the possibility of 'spontaneous' or 'automatic' (SISa model) infection for their study of positive and negative emotional states.
Indeed, they did prove that their epidemiological model could be used to determine the both the rate and longevity of the emotional state. Data was derived from the Framingham Heart Study, a longitudinal study of the residents of Framingham, MA since 1948, and once entered into the mathematical formulations, they become very precise.
It was learned from the data that the probability of becoming discontent is twice that of becoming content based on the frequency of contact with a discontent member of one's social network (0.04 per year per discontent contact vs. 0.02 per year per content contact). The average life span of discontentment, however, is half that of contentment - a contentment 'infection' lasts for 10 years on average, while a discontentment infection lasts for 5 years on average.
Social networks spread more than Swine flu, obviously. And the Harvard/MIT 'infectious emotions' model should serve as a theoretical framework for studying many other infectious behaviors.
At any rate, now we know with certainty that laughter is contagious and so is happiness. If you want to be happy for the rest of your life... keep hanging out with happy people.
Proceedingsof the Royal Society via Wired.com