This doesn’t mean there are techniques that give you total control over someone. People are far too complex, no matter what pick-up artists would have you believe. Nonetheless, there are some scientifically recognized means for getting people to comply with your wishes.
There’s the “foot-in-the-door” technique. A friend asks to borrow money for the bus. You agree. Then they ask if they can borrow more for a sandwich. You agree again. Then they say why not go to the bar, catch up over a few drinks? As long as you’re OK to pay, they don’t have any money, remember? You think, “Sure, it’s only a few drinks.” Then it’s a few more and suddenly they’re asking to borrow money for a taxi as they’ve missed the bus, and you sigh and agree because you’ve said yes to everything else.
If this so-called friend had said, “Buy me dinner and drinks and pay for me to get home in a convenient manner,” you’d have said no, because it’s a ridiculous request. But that’s exactly what you’ve done. This is the foot-in-the-door (FITD) technique, where agreeing with a small request will make you more amenable to a larger request. The requester has his “foot in the door.”
FITD has several limitations, thankfully. There has to be a delay between the first and second request; if someone agrees to loan you $5, you can’t ask for $50 ten seconds later. Studies have shown FITD can work days or weeks after the initial request, but eventually the association between the first and second requests is lost.
FITD also works better if requests are “prosocial,” something perceived as helpful, or doing good. Buying someone food is helpful, then loaning them money to get home is also helpful, so more likely to be a request that’s complied with. Keeping lookout while someone scrawls obscenities on their ex’s car is not good, so driving them to their ex’s house to throw a brick through their window afterwards would be refused. Deep down, people are often quite nice.
FITD also needs consistency, for instance, loaning money, then loaning more money. Driving someone home doesn’t mean you’ll look after their pet python for a month. How are these things related? Most people don’t equate “give a ride in my car” with “have a giant snake in my house.”
Despite limitations, FITD is still potent. You’ve probably experienced the family member who gets you to set up a computer and ends up using you as 24/7 tech support, for instance. That’s FITD.
A 2002 study by N. Guéguen shows it even works online.7 Students who agreed with an emailed request to open a specific file were more likely to take part in a more demanding online survey when asked. Persuasion often relies on tone, presence, body language, eye contact and so on but this study shows these aren’t necessary. The brain seems worryingly eager to agree with requests from people.
Another approach actually exploits a request that’s been denied. Say someone asks you if they can store all their possessions in your house because they’re moving out. This is inconvenient, so you decline. Then they ask if they can instead borrow your car for the weekend to move to their stuff elsewhere. This is much easier, so you agree. But letting someone use your car for a weekend is inconvenient, just less so than the original request. Now you’ve got someone using your car, and you’d never usually agree to that.
This is the door-in-the-face technique (DITF). It sounds aggressive, but it’s the person being manipulated who is “slamming the door” in the face of those making demands. But slamming a door in someone’s face (metaphorically or literally) makes you feel bad, so there’s a desire to “make it up” to them, hence agreeing with smaller requests.
DITF requests can be much closer together than FITD ones; the first request is denied, so the person hasn’t actually agreed to do anything yet. There is also evidence suggesting DITF is more potent. A 2011 study by Chan and her colleagues used FITD or DITF to compel groups of students to complete an arithmetic test.8 FITD had a 60 percent success rate, while DITF was closer to 90 percent! The conclusion of this study was that if you want schoolchildren to do something, use a door-in-the-face approach, which is definitely something you should phrase differently when announcing it to the general public.
The potency and reliability of DITF may explain why it’s so often used in financial transactions. Scientists have even assessed this directly: a 2008 study by Ebster and Neumayr 9 showed the DITF to be very effective when selling cheese from an Alpine hut to passers-by. (NB: Most experiments don’t take place in Alpine huts.)
Then there’s the low-ball technique, similar to FITD in that it results from someone initially agreeing to something, but which plays out differently.
Low-ball is where someone agrees to something (a specific price to pay, a certain amount of time to do a job, a specific word count for a document), then the other person suddenly increases the initial demand. Surprisingly, despite frustration and annoyance, most people will still agree with the increased demand. Technically, they have ample reason to refuse: it’s someone breaking an agreement for personal gain. But people invariably comply with the suddenly increased demand, as long as it’s not too excessive: if you agree to $70 for a used DVD-player, you won’t still agree if it suddenly costs your life savings and firstborn child.
Low-ball can be used to make people work for free! Sort of. A 2003 study by Burger and Cornelius of Santa Clara University had people agreeing to complete a survey in return for a free coffee mug.10 They were then told there were no mugs available. Most still did the survey, despite not getting the promised reward. Another study by Cialdini and his colleagues in 1978 reported university students were far more likely to show up for a 7 a.m. experiment if they’d already agreed to show up at 9 a.m., than if they were initially asked to show up at 7 a.m.11 Clearly, reward or cost aren’t the only factors; many studies of the low-ball technique have shown that actively agreeing to a deal, willingly, before it’s changed is integral to sticking to it regardless.