Take an African animal and put it in Norway , or Seattle. Do you think it would be happy in that climate? But that's us. Growing up in Pennsylvania, I was familiar with the long summer days and long winter nights of temperate regions - but the week between Christmas and New Year, standing in Regent's Park in London during my first visit to the U.K., and looking at the tired glow of the sun through the clouds barely shoulder-high on the horizon at 11 in the morning - I started to realize why humans are so eager to to reduce their latitudes.
In the U.S., much of which is at sunnier latitudes, estimates of sufferers of clinical seasonal affect disorder or just winter blues run 10-15%. There are also claims that alcoholism correlates positively with latitude.
So I was not surprised when I looked at a sunshine map of the U.S., and saw a stripe of cloudiness along the Appalachians that matched (somewhat) with a portion of the unhappy stripe in a recent happiness survey:
The unhappy stretch extends from the west side of the Appalachians in Tennessee and Kentucky all the way through Arkansas and Oklahoma, which aren't as gloomy. I often point out to whiners in the Pacific Northwest that they aren't any cloudier than the poor folks in West Virginia and central/western PA.
Oddly enough, I noticed earlier that the unhappy stripe correlated even better with voting Republican for President in the 2008 U.S. elections.