An even more convincing hypothesis is that depression is simply contagious. (That is, hearing a depressing thought can be almost as depressing as coming up with it yourself.)
This is supported by research on social networks: happiness and depression are both contagious.
As an interesting detail, happiness seems to be more contagious than depression, so befriending a lot of people will on average increase your chances of getting “infected” with happiness.
Of course the claim itself sounds very plausible, but I’d like to see the research, because your short summary makes me suspicious that it makes a correlation-is-not-causation kind of mistake. In other words, does the research support the claim that happiness is contagious or that it is clustered? Is there even a temporal aspect present in the analysis?
In the source I’m using, they claim to have checked for it via “mathematical analyses”, but no further details are given. They do provide a reference to their their actual paper. This paper is also mentioned as having come to similar conclusions.
I can’t remember where I saw the research either (it was recent though, maybe on Hacker News), but they did check casuation/temporal effects by following people over time and seeing that when one person became sad, people within a few social links of them were more likely to become sad, etc.
There is extensive documentation on what many call the Framingham, Mass. longitudinal study, where they studied as many people in the small town for as many years as they could. I think the results of that are the most reliable on the question of the “contagiousness” of happiness and sadness.
I’m not entirely sure, but I think most of those research fail to discriminate between happiness/depression actually spreading vs. happy/depressed people simply tending to hang out together.
This is supported by research on social networks: happiness and depression are both contagious.
As an interesting detail, happiness seems to be more contagious than depression, so befriending a lot of people will on average increase your chances of getting “infected” with happiness.
Of course the claim itself sounds very plausible, but I’d like to see the research, because your short summary makes me suspicious that it makes a correlation-is-not-causation kind of mistake. In other words, does the research support the claim that happiness is contagious or that it is clustered? Is there even a temporal aspect present in the analysis?
In the source I’m using, they claim to have checked for it via “mathematical analyses”, but no further details are given. They do provide a reference to their their actual paper. This paper is also mentioned as having come to similar conclusions.
ETA: And here’s the appendix they keep mentioning in the paper.
I can’t remember where I saw the research either (it was recent though, maybe on Hacker News), but they did check casuation/temporal effects by following people over time and seeing that when one person became sad, people within a few social links of them were more likely to become sad, etc.
Kaj—nice! Can you point me to any good references on this?
There was a lot of buzz last year with Are your friends making you fat?
There is extensive documentation on what many call the Framingham, Mass. longitudinal study, where they studied as many people in the small town for as many years as they could. I think the results of that are the most reliable on the question of the “contagiousness” of happiness and sadness.
See my reply to DanielVarga above.
I also mentioned other interesting tidbits from the same book previously. Guess I should do a summary here soon.
I’m not entirely sure, but I think most of those research fail to discriminate between happiness/depression actually spreading vs. happy/depressed people simply tending to hang out together.