I actually looked this up a little while back while talking to a friend about how impatient drivers are here. There are studies that show this to be the case.

Plus it makes your brain perform more poorly. This all tracks with Florida.

it’s true, when it’s unbearably hot and i have no option for reprieve, my patience for people drops to basically nothing

that said, i go out of my way to avoid human contact, rather than act an asshole to everyone in sight