Notice how most of the southern states are all happy.
Is it because they have simple lives and not much expenditure?
Or do they love Tornado's so much :P
Many factors.
Smaller populations.
Conservatives (The US version, so Liberals everywhere else in the world) and Religious people are constantly shown in studies to be happier than Liberals (The US version, so Socialists everywhere else in the world) and Areligious people.
They're generally not as healthy in southern states, which means they eat good tasting food and have more fun rather than eating healthy (boring) and stressing out over exercise.
Living expenses, in general, are much lower down south so the same amount of money goes farther.
Better climate.
And tornados are more common on the Great Plains and in the upperish Mid-West than in the south.
Why are the unhappiest states also the ones with the highest population? Are people stupid enough that they enjoy being miserable?
Hell is other people. -- Jean-Paul Sarte.
A witty saying proves nothing. - Voltaire