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.

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

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