Just Like Stupid Humans, Fish Get Cocky When They Drink

We humans love booze as liquid courage, but we're not the only ones who feel extra capable after a few swigs. New research shows that a tipsy zebra fish will swim faster than the sober fish in its school—like a big showoff. And just like humans, the sober fish will speed up rather than be outdone by a drunkard. Humans: basically, we're just big fish.

The research, published this week in Alcoholism: Clinical and Experimental Research, studied the social effect that sober peers would have on a single drunken zebrafish. Surprisingly, like the hero and villain in a comic book, the sober and drunk fish each had an influence on the others' behavior. As Professor Maurizio Porfiri, whose lab did the study, explains:

It is clear that the untreated fish were matching the swimming speed of the alcohol-exposed fish, and this correlation was especially strong at an intermediate level of alcohol exposure. At very high or low levels, the influence decreases.

In other words, tipsy fish get confident, while drunk-off-their-rocker fish get clumsy. When the drunk fish look like they've got it under control, the sober fish follow their lead. And you thought being at the top of the food chain made you so special.

There's a scientific use for this knowledge: zebra fish have a particularly complex set of social behaviors, and their nervous systems are affected by alcohol in a way that's very similar to our own boozed-up brains. Figuring out the dose-response interaction in zebrafish can help us get a better understanding of how alcohol and other substances affect our own cognition. Plus, drunk zebrafish are way more cooperative than humans.

Finally, since you were wondering: The researchers got the fish drunk by pouring a precisely-metered dose of ethanol in the aquarium water. In other words, these fish weren't just sipping; they were swimming in booze. [Alcoholism: Clinical and Experimental Research via PopSci]

Image: Shutterstock / Sharapkov Alexey