First pubished in 2009

YouTube, bad gifts, and the plague all have something in common: they spread radially within interconnected groups of people. Now you can add happiness to that list.

A new study shows that happiness is more than an individual experience, it’s a collective phenomenon. Happiness disperses within three degrees of social separation. In other words, you affect the emotional state of your friends, their friends, and even friends’ friends’ friends. And the ripple of emotion that you launch into your social sphere can last for nearly a year.

“Everyday interactions we have with other people are definitely contagious,” Professor Nicholas Christakis of Harvard Medical School told NPR. But sex plays a surprising role in the transmission of emotion. Happiness spreads more readily through same sex relationships than through opposite sex relationships. Which means you may have more of an impact on your best friend’s mental state than her boyfriend does.

Christakis and co-author of the study, James Fowler of the University of California-San Diego also discovered that women are less happy than men. Happiness is directly linked to physical health. Happy people tend to avoid illness and live longer lives than unhappy people.

The implications of these findings are enormous. Women have the unique opportunity to influence the wellbeing of other women simply by concentrating on their own happiness. Instead of worrying about pleasing others, we should spend more time learning what pleases us, and then doing it.

During the season when everything seems to be contagious do everyone a favor and skip the re-gifting and sneezing. Instead, contribute to societal health by infecting everyone you know with happiness.

Watch the video about happiness in social networks on NPR.

UCLA neuroscience and human-behavior researchers have demonstrated a link between fairness and reward in the brain. “Receiving a fair offer activates the same brain circuitry as when we eat craved food, win money, or see a beautiful face,” lead author Golnaz Tabibnia explained in UCLA’s Newsroom. 

The experiment utilized the ultimatum game, a test in which money is divided between two parties. The “proposer” determines how the money will be split. The “responder” can either accept the offer (in which case both parties keep the cash) or reject it (in which neither party gets anything, thus penalizing the proposer for making an unfair offer). There’s no chance for reciprocity because participants only play once.

During the test, Tabibnia and her team charted the responders’ brain activity with functional MRI. When a proposed offer was fair, such as $5 out of $10, the reward center in the responder’s brain was triggered. On the contrary, when a responder received a lopsided offer, like $5 out of $23, the region associated with disgust was aroused.

Even though responders in both examples would get the same amount ($5), most who received a fair deal ($5 out of $10) accepted the offer while nearly half of those who were given a bad deal ($5 out of $23) rejected it. Fewer than 2% accepted offers with a 10% – 90% split. This is significant because logically even 10% of the money would have been a gain.

“We had never thought of ethics or fairness as being tied to neurons,” Joy Hirsch, Ph.D, of the Program for Imaging and Cognitive Sciences at Columbia University in New York, told WebMD.

“Certainly money is rewarding,” Tabibnia stated in the Los Angeles Times. “But more and more research is suggesting that our social relations with other people…can be very strong determinants of our happiness and satisfaction.”

Technology has made travel fashionable and profitable. And moving away from home is not only a rite of passage, it’s a status symbol. Clearly, we’ve become a transient society that bends its surroundings to fit its needs. We control our environment; it doesn’t control us. Or does it?

“We like to think we’re cool, 21st-century people, but the basic connection to the land is still big. We haven’t evolved that much,” argues Professor Glen Albrecht.

Albrecht and a team of Australian researchers have discovered what they believe is a new form of depression related to changing environmental conditions. They call it “solastalgia,” a combination of the Latin words for comfort (solacium) and pain (algia).

Solastalgia is the “palpable sense of dislocation and loss that people feel when they perceive changes to their local environment as harmful,” Albrecht explains. “It’s a form of homesickness one gets when one is still at home.”

The team’s research was conducted in New South Wales among communities where land has been ravaged by coal mining. And man-made climate change threatens to make solastalgia a universal disorder.

Already people across the globe are becoming wary of “freak weather” including severe drought, colossal tropical storms, and low snowfall. The Inuit use the word uggianaqtuq, which means weather has become a stranger rather than a trusted friend.

In a blog post in Wired magazine, Clive Thompson wagers that “the next victim of climate change will be our minds.” Are you still willing to bet we’re in control?