How do you get someone to lose interest in their hobby? Pay them to do it

How do you get someone to lose interest in their hobby? Pay them to do it:
Think a little money would make you more interested in your hobbies? Think again. The overjustification effect says that paying someone for a task they enjoy is a sure way to get them to drop it. All it takes is a little money and a little planning to ruin anyone's pleasures.
One of the time-honored ways that guidance counselors try to steer high school students to their ideal careers is asking them what they would do if they didn't have to earn any money. The realistic answer is most likely to be "play video games, sleep in, and eat Cheetos," none of which are compensated. Still, a lot of kids will say things like, "work on fancy cars," or "travel around on cruise ships," or "rile people up on facebook." The counselor will conclude that the person who wanted to play around with cars is meant to be a mechanic, the person who wants to work on cruise ships should be a cruise ship director, and the person who wants to rile people on facebook should either be a social media consultant or walk out into a snowstorm without a jacket or a map. The idea is that, if you want to do something anyway, getting money for it will make for a happy life.
Perhaps a better piece of advice is to never let your hobby become a career. That's not only because the demands of a job can spoil a pleasure. Psychologists have observed a phenomenon called the overjustification effect. People identify activities that they'd do for free. The psychologist offers them some small monetary compensation for it. In some studies, that is enough to snuff out interest. One study, involving blood donation, showed that women (but not men) tended to drop interest in donating blood if offered some small monetary reward. If they could give the reward to charity, they were interested again.
More commonly, when the reward drops away, even the pre-existing interest disappears. If people get used to being paid for things, they stop wanting to do it when they're not paid. Similar studies have been done on animals, with similar results. Mice who ran a maze for a reward which decreased over time slowed their pace until they were even slower than mice that were offered the decreased reward in the first place. When we get used to higher compensation, a sudden drop decreases motivation beyond base levels.
But there are ways around the effect. One of the best is a scale of pay for better results. One study showed that people offered a pay scale that they felt wasn't commensurate with the skill shown in the task were demotivated, while those who thought they were compensated fairly for their skill got a motivational boost. Less pleasantly, people who were underpaid were often more motivated than those who were overpaid.
Still, if you had a sadistic streak and a little extra cash, you could anonymously hire your worst enemy to engage in activities that they enjoyed for a few months. You could even over-pay them. When you dropped them as clients, you could actually cause them to lose not only the hope of a paid job doing what they loved, but rip away the love they had for the activities in the process. Who knew the best way to break a person is to, briefly, reward them?
Image: PD Photo
Via Wiley, Science Direct, and PsycNet.