This episode of SciShow is sponsored by Snickers.

It’s not. Though it should be!

Get on it, Snickers! [♪INTRO]. It’s happened to the best of us. It’s close to dinner time, your stomach is grumbling...

All of a sudden your significant other’s foot tapping becomes too much to bear, and you lash out. Your partner has fallen victim to hanger, the grumpiness you feel when you are hungry. And it isn’t an excuse—it’s an actual physiological and psychological phenomenon.

Science has shown that hanger is real. For example, people jab more pins into a voodoo doll of their spouses or choose to blast loud noises at their partner when their blood glucose levels are low. Psychologists think that this may be because hunger impairs self-control.

Not acting impulsively takes brainpower, and when the brain’s low on fuel, it just doesn’t have the energy to hold back. Another explanation is that hanger is basically a mistake your brain makes when you’re not sure what’s causing your body to feel bad. That’s because some psychologists think feeling emotions is actually a combination of what’s physically going on in your body and what your mind thinks is the reason for that.

So if you don’t realize what’s making you feel off, you might pick a different emotion. When you haven’t eaten in a while, you might attribute your rumbling stomach, tiredness and fuzzy head to other feelings that cause those reactions, like stress or even anger. No really—this is a thing.

Scientists have shown that this can happen. For example, experimenters in a 2016 study irked 236 college students by making the computer they were using crash. Those that had fasted before the test reacted more negatively, seeming to add their hunger-related feelings to the frustration induced by the tech glitch.

They even reported more hatred towards the experimenter. Hatred! And that might sound extreme, but it’s an honest mistake, because hunger and anger look a lot alike physiologically.

Some of the same brain regions are activated both when you feel angry and when you’re hungry. And that’s because the same brain chemical, a tiny protein called neuropeptide Y, both prompts your body to eat when your energy reserves are low and regulates aggression. Actually, it makes a lot of sense, because hunger is your brain’s way of signaling the release of hormones that increase the amount of glucose into your bloodstream so that your tissues don’t starve.

And those same hormones are released in stressful situations, when a boost of glucose could help you out muscle a predator or run away. And the connection between hunger and aggression might be more than a bodily coincidence. For our ancestors, food wasn’t always a reliable thing.

Their feelings of hunger were a sign that food was scarce, so whatever they found when hungry was probably worth fighting for. Being hangrier, and thus more aggressive about securing meals, might have helped them get the fuel they needed to out compete more complacently hungry rivals. And the legacy of that hanger lives on in us today.

So the next time you feel yourself about to bubble over with frustration, remember:. It may be your body’s way of decoding your empty stomach. So go eat a snack!

But not a Snickers. Yet. Thanks for asking, and thank you to our actual President of Space today, who would just like us to say that it’s “Not SR Foxley.” It’s usually SR Foxley, but this time it isn’t, and that’s the only thing that this person wanted us to say.

Without our Patreon patrons, like SR Foxley and also Not SR Foxley, we wouldn’t be able to make SciShow and answer all of your maddening questions about the universe. Thank you to all those people. Everyone except Snickers. [♪OUTRO].