Nature or Nurture? It looks like Nature strikes again.
As noted in Born to be Happy by Jeremy Laurance, writing for the New Zealand Herald, research published between 2009 and the present has linked a gene to people's 'base state' of optimism and happiness or pessimism and gloominess.
The finding is the first to demonstrate a link between the gene, called 5-HTT, and satisfaction. People with the long version are more likely to be cheerful while sulkiness is the default position of those with the short version.
Well, I think I know which version I've got.
But, more specific to our ever ongoing meta...
The 5-HTT gene, which regulates the brain chemical serotonin, has been indirectly linked with happiness before. In research published in 2009, scientists showed that people with the long version of the gene had a subliminal tendency to avoid negative images and select positive ones. They concluded that the gene contributed to "attentional bias in the selection of emotional stimuli".
So folks with the shorter version tend to fixate on the negative side of things, and folks with the longer version on the positive side.
Given that we've seen elsewhere that voter turnout looks to be partially controlled by genetics, and that liberals and conservatives actually use their brains differently, I shouldn't be too surprised that even our meta comes down to genetics...