How do restaurants hack your brain? Cracking the code that makes you spend more money – Austin

Picture the scene. You’ve given yourself a break from cooking and you’re out for a meal with some friends – nothing too fancy, just something a little different that’s reasonably priced. And there’s some good deals on tonight.

Then why is it that you’re on your 4th glass of wine? Or “all you can eat” is one bowl of egg fried rice and a few spring rolls?

If you’re not normally an impulsive drinker or a small eater then why the sudden change in traits? Don’t worry, you haven’t been possessed – but brainwashed.

Whilst it’s highly likely you weren’t greeted by a man outside the restaurant swinging a pocket watch rhythmically, everything from the menu’s layout to the size of the plates is geared so that ultimately you spend more than you originally thought you would. They are a business after all.

And the establishment know full well you aren’t going to consciously make the decision to have more food or drink, so optical illusions are a go-to technique for restaurants. Take the two dark circles below:

Which is the bigger black circle? It’s not obvious straight away but surely the one on the left looks a little smaller… doesn’t it?

In fact, the two circles are exactly the same size. The effect of the right dark circle appearing bigger than the left one is known as the Delbeouf illusion, discovered by Belgian philosopher and mathematician Joseph Remi Delbeouf in 1865. In the context of a restaurant, you can picture them as lumps of food on two different sized plates. Why? Where you might pay by the dish in a pub or a diner, you can expect your plates to look a little like the left half of the figure. It looks less like a “big plate of food” so you’re less likely to feel satisfied and thus more likely to have room for a second dish or a dessert.

However, in an all-you-can-eat establishment, you might notice the plates they provide are considerably smaller than what you might find down your local. You’ll be more tempted to fill the plate and feel stuffed after one or two runs of the buffet gauntlet. Suddenly that set price per person doesn’t seem such good value!

It doesn’t stop at the size of the plates either, Dr. Brian Wansink and Dr. Koert van Ittersum (both professors of Economics and Business at Wageningen University and Cornell University respectively) took the illusion one step further and performed a series of experiments to observe the effects of various other factors on eating behaviour – specifically the contrast in colour between the food and the plate it is served on, as well as the food and the colour of the table cloth.

By randomly giving a number of party attendees red plates or white plates and giving them the option of red sauce or white sauce for their pasta, it was revealed that people who matched their sauce with their plate served themselves 30% more pasta on average than those with contrasting pasta and plates! Whilst this isn’t an effect of an illusion per se, it comes down to what looks more aesthetically pleasing, and hence more appetizing.

On the topic of aesthetics, how would you write the price of something? Does it matter? £10.00, 10.00 and “ten pounds” all mean the same thing…

Although they are similar, a study in a restaurant at the Culinary Institute of America in New York revealed that customers given menus with prices in the second format (10.00) spent considerably more than those presented with words. The suggested theory behind this is that the brain is more comfortable with spending 10 ‘something’ and dropping the unit of currency, rather than being shown literally “ten dollars” (they’re the kids in America).

The next trick in the book?

Play music. It’s a fact that increased auditory simulation directly increases consumption of food and drink and, depending on the genre, it can have varying affects.

Music plays a big and unsurprisingly effective part in setting the atmosphere of a restaurant; it was found that loud rock music led to a higher consumption of alcohol, and simply playing loud music in general raises the heart rate and perspiration levels (all signs of stress) which causes people to eat more.

Perhaps the greatest finding however is that you are more likely to order expensive wine when listening to classical music rather than the UK top 40… Bach is more likely to make you splash out than Beyoncé.

This has been a public service announcement, and even armed with the knowledge that (some) restaurants are out to scam you, there’s a good chance we’ll continue to fall for these tricks because at the end of the day, it’s food, glorious food, and we’re anxious to eat it.