Heineken is playing a visual trick on you every time you go to the beer aisle. Next time you’re standing there mulling over Budweiser or the Dutch brew, just take a moment to look at the latter’s logo. You might not notice it at first, but in comparison to the other letters, the three “e”s in Heineken are slanted slightly backwards, their bottoms curved, grinning up at you with a toothless smile. “There’s nothing human about a typeface, but this slightly turned “e” gives the feeling of smiling,” says Marc Andrews, a creative director and psychologist from Amsterdam. “And this gives you a totally different relationship to the brand.”

It’s a happy, oddly humanistic logo, and Heineken is hoping that will be enough to prompt you to grab its six pack over the king of beers. The brand’s tactic is subtle. So much so, you probably don’t notice it consciously, which is the entire point. We’re surrounded by visual cues nudging us to buy this or prodding us to do that, and most of the time we have no idea it’s even happening.

In his new book Hidden Persuasion, Andrews, with social psychologists Matthijs van Leeuwen and Rick Baaren, explores 33 of the sneakiest tactics advertisers deploy while hawking their products. These hidden persuasions, as Andrews calls them, are a driving force behind advertising world’s efficiency, and they’re way more common than you might think.

"People think that their decisions and choices are most of the time made consciously and rational, relating to their wishes, interests and motivations," explains Andrews. "Fact is, that most of our decisions in daily life are made on an unconscious level, which means we are quite vulnerable to persuasion attempts which effect our unconsciousness."

>These hidden persuasions are a driving force behind advertising, and they’re way more common than you might think.

We humans want all sorts of things. Some are intangible: Safety, health, the desire to fit in with our peers. Others are just stuff: That shiny car, some shoes, a hamburger. It’s the job of advertisers to make sure we buy this stuff, and the best way to do that? Exploit our inherent vulnerabilities. Advertisers have plenty of ways to manipulate our behavior. See below and in the above slideshow for some of the most effective techniques.

Anthropomorphism

The Heineken example we cited is just one example of using anthropomorphism to sell a product. The thinking here is simple: The more human a product is, the more connected we feel to it. We develop the tendency to anthropomorphize early on when we get attached to things like blankets, binkies and cartoon characters.

“We tend to add thoughts and emotions to objects in a similar way to how we would experience things ourselves,” explains Andrews. This in turn makes us empathize with things like beer bottles or cleaning products. “The more we like and advertised product and have ‘feelings’ for it, the more likely we are to bond with it, and thus buy the advertised product.”

Trustworthiness

Every face you see in an ad is carefully selected based on lots of criteria. One of those things? How trustworthy that person looks. We rely on visual cues to unconsciously figure out how we feel about something, and it turns out some people just look more trustworthy than others. Beyond obvious signifiers like a creepy mustache, things like facial width-to-height ratio (the distance between the two extremes of the cheekbones and the distance from the upper lip to the eyebrows) can clue us in to how trustworthy a person is. People with higher faces are perceived as more trustworthy than those with wide faces, as are brown eyes versus blue.

Scarcity

If you’ve ever bought airline tickets on Kayak, you’ve undoubtedly seen the little alert telling you “Only 1 ticket left at this price!” Nothing kicks you into buying mode like the fear of paying more for the same product or missing out on it altogether.

Turns out, FOMO extends to buying stuff, too. Andrews says this is partially because it's been ingrained in our minds that the expensive things tend to be scarce (gold, diamonds). Scarcity also suggests that other people like the product (hello, social proof). Andrews writes that the last reason scarcity technique works so well is that it reminds us that our freedom of choice will soon be gone.

Social Proof

Among the most effective tactics advertisers can use is tapping into our social insecurities. It makes sense; we go to doctors, hairstylists and restaurants based on our friends’ recommendations, and we’re just ask likely to buy something because it’s gotten the stamp of approval by someone we know and admire.

“The more people who approve of something, the more likely we are to like it, too” says Andrews. Just look at Facebook and its snowball “liking” effect. Even saying something as simple as “Nine out of 10 people choose Tide” or “The majority of people prefer Wonder Bread” works exceptionally to influence human behavior, Andrews adds. So much for individuality.

Acknowledging Resistance

The best way to get you to buy something is to make you believe you don’t have to buy it. Advertisers have mastered the art of reverse psychology, and it works to their advantage. The fact is, nobody likes to be told what to do. “No one likes to feel like they’re being persuaded,” explains Andrews. Which is why advertisers try to convince you that you have a choice in the matter. Transparency, or a brand acknowledging its shortcomings is one way they go about it. Another is saying things like, “you’re free to go with that other vacuum” or “I know you might not agree to this, but…” By playing to the fact that consumers don’t want to be persuaded, advertisers are, in fact, persuading you to like their brand.

Hidden Persuasion is out now. There's only one copy left on Amazon. Just kidding.**