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Whenever you go out for dinner or drinks, just know this: your brain is being hacked. Like with most businesses, the goal is to make money, so it kinda makes sense that restaurants and bars would do whatever they can to get you to spend more of it.

But there are a lot more ways they can manipulate you than you might realize. From the adjectives on the menu to the size of the plates, establishments can use all kinds of psychological tricks to influence your behavior. Some of them are so hardwired that even after watching this video, you still might be fooled.

But at least if you know what's happening, there's a chance you can take back control. The mind-hacking begins with the menu. For example: Have you ever noticed that a lot of restaurants list prices as plain numbers?

There'll just be a “15” next to the crab cakes, with no dollar sign or any other indication that it's a price. That's not an aesthetic choice. Studies have shown that people spend more when menus don't have dollar signs, probably because it keeps you from thinking about how much money your order will cost.

There's also a lot of thought that goes into how the items are listed. The options aren't “hamburger” or “baked fish” — instead, they're described as “Joe's meaty burger” or “succulent Italian fillet.” That's because researchers have found that adding colorful descriptors can increase sales by up to 27%. So you might want to translate the choices in your head before you decide what to order.

Restaurants and bars can also influence both how much you spend and how much you consume by using glasses and dishes with certain shapes and sizes. One thing they can do is vary the size of their dishes to take advantage of what's known as the Delboeuf illusion, where two identical circles look different based on the size of circles around them. Not to be confused with the Labeouf illusion, where two identical circles are actually props in a short experimental film.

In the Delboeuf illusion, if one of the circles is surrounded by a third circle that's just a little bigger, the inside circle will look larger than its twin. But if the outside circle is much bigger, the inside circle will look smaller. Since food on a plate is essentially a circle of stuff surrounded by the circle of the plate's edge, this illusion can make the same portion look bigger depending on the size of the plate.

A 2012 study in the Journal of Consumer Research confirmed this by showing that people overestimate portions when they're using large plates, serving themselves more than they really wanted. With small plates, they serve themselves less. The Delboeuf illusion is so convincing that studies have found you'll actually feel more full when you eat a meal from a smaller dish.

That's why all-you-can-eat buffets tend to keep their plateware small — so you think you're eating more when you really aren't. Meanwhile, restaurants where you pay based on what you order tend to serve their entrees on large platters, hoping to convince you that you still have room for dessert. There's also a lot they can do with glassware.

Research has shown that people are willing to pay much more for drinks if you match their expectations when it comes to the shape of the glass. Because of cultural influences, we think some drinks simply belong in certain glasses—like a rounder, larger glass for red wines than whites. And when there's a mismatch, that creates cognitive dissonance—the psychological stress we feel when a situation leads to conflicts between our attitudes, beliefs, or behaviors.

You might not think of drinking hot chocolate from a water glass as something that would cause psychological anguish, but it does! Which means we find the overall experience less pleasant, and we don't want to pay as much for it. Certain shapes can also get you to drink faster.

In a study published in PLoS ONE in 2012, researchers found that we drink beer faster from curved glasses than straight ones. That's probably because our brains tend to judge how much liquid is left based on how far up the glass it reaches, even if the glass is much wider at the top. So with a curved glass, it's harder to pace yourself, and by the time you think you've finished half your beer, you're actually much more than halfway through.

You might end up finishing the beer much faster than you wanted … and the faster you drink, the faster you need a refill. We also tend to think tall, skinny glasses contain more than short, fat ones, even when they don't. Studies have found that we pour more into short, fat glasses, and we drink more from them—up to 88% more.

That might come from what's known as the horizontal-vertical illusion, where vertical lines seem longer than horizontal ones. Psychologists aren't totally sure why the illusion works, but it might be because our visual field is wider than it is tall. So, like, a line of the same length takes up a greater percentage of what we see vertically than it does horizontally, which makes us think it's bigger.

Restaurants can even influence the way your food or drink tastes based on how they serve it to you. One tactic uses what's known as shape symbolism, where we associate roundness with sweetness and angles with bitterness. Like with the horizontal-vertical illusion, we're not sure why this is, but it's possible that we conflate bitterness and physical sharpness because they can both be signs of danger.

Whatever the reason, shape symbolism makes us perceive chocolate cut into rounds as sweeter than the exact same bar in chunks, or beer from a curved glass as fruitier. And that's just the beginning. A lot of flavor manipulation comes from a phenomenon called sensation transference, where we transfer the properties of the plateware or utensil to the food we eat from it.

So for example, if you want to make soda taste cooler and more refreshing, you can put it in a cool-colored container—a tip Pepsi took to heart. Even the heft of your cutlery can make a difference. Since we automatically associate weight with quality, we'll think yogurt tastes better when we're eating it with a silver spoon than when we eat it with a plastic one.

And of course, as Iron Chef taught me, plating also matters. In one study, researchers presented 60 people with a salad of the exact same ingredients tossed, neatly sorted, or arranged to look like a famous Kandinsky painting. Before they even tried it, participants said they knew they'd like the artistic salad more, and ultimately, they rated it 29% tastier than the other salads.

So if you're trying to reduce how much you eat and drink — or how much you spend — you might want to keep an eye out for some of these tricks the next time you go out to eat or meet up at the bar with your friends. Because practically everything about the place is trying to sell you something. Thanks for watching this episode of SciShow Psych!

If you're interested in learning about more ways businesses can use psychology to manipulate people, you can check out our video about the tactics advertisers use to persuade you. [♪♩OUTRO].