In the dark bars up there are the number of drinks the college students thought they would have to drink in order to have the adverse consequences listed. The white bars are the ACTUAL number of drinks they’d have to have.
Most people are fixated on the difference between the black bars and the white bars. College students are dangerously overestimating the amount of alcohol they need to do stupid things.
I see something else. There is a shockingly little difference between the number of drinks it takes for the least worrisome of these things (hangover) to really bad things (blackout). And it even takes less drinks to achieve unwanted sex than a hangover!
Bottom line – when you get to 7 drinks (on average), everything bad starts to happen pretty fast. It doesn’t take much more than 7.