In Action

Just knowing you have a caffeine hit coming tends to perk you up. We value more than just the chemicals here. To see this in action, find someone who is a certified caffeine addict. It doesn't matter if she is into tea or coffee, as long as she is really into it. I'd wager that she is also rather particular about how she takes it too. Does she have a favorite mug? Does she like the milk poured in before the tea? Is she picky about how the coffee beans should be ground?

Now, find something that doesn't affect the taste of the drink, but that she always does—it doesn't really matter what. Stop her from doing it. Give her coffee to her in a glass. Put the milk in after the tea. Do the opposite of the way she likes something done.

She'll freak. Or at the very least she really won't like it.

The more she's into caffeine, the more particular she'll be about the drink being made and delivered in just a particular way. Weird, eh? She's addicted to a complex molecule; the delivery of it into her system, in any form, is enough to create the positive effects of the drug and remove any associated withdrawal symptoms. But she insists on the precise method of delivery. How come?

How It Works

By chemically hacking the reward circuitry of the brain, caffeine gives us a stark view of a couple of the basic animal learning mechanisms. These are called classical conditioning and operant conditioning and are associated with the scientific school called behaviorism, which dominated modern psychology until the 1970s.

You've probably heard of Pavlov, the Russian scientist whose experiments with dogs established the basic principles of classical conditioning. This basically says that, if something happens at the same time as something rewarding, it comes to be associated with the response to—and can eventually substitute for—the rewarding stimulus. In this case, the caffeine is the intrinsically rewarding stimulus (because it hacks your reward circuitry) and everything else (the smell, the taste, the cup, the time of day) comes to be associated with the reward. This is why decaf can actually work wonders (particularly if your subject doesn't know it is decaf, thanks to the Placebo Effect [Hack #73]) and why just making a cup of coffee makes me feel more alert, even without drinking it. When I used to write essays late at night at college, just the sound of the kettle reaching the boil would make me feel more alert. The response (perking up) becomes associated with the things that normally accompany the actual cause (the caffeine)-the smell of coffee, the sound of the kettle boiling, and so on.

The other major kind of conditioning, operant conditioning, states that rewards reinforce the actions that precede them. While this sounds pretty obvious, you can get a very long way just by looking at the world through the lens of "What actions are rewarded? Which are punished?" In the case of our caffeine experimentation, everything leading up to the consumption of the caffeine is rewarded. No wonder we develop superstitions about how the caffeine should be prepared. In fact all drugs are associated with preparation rituals: from the Japanese tea ceremony, to clinking glasses of beer, and up to the harder drugs and things like the shooting rituals of heroin users.

These learning mechanisms are intrinsic and are found in all complex animals. They are deeply programmed into our brain and can operate without conscious effort or memory. Decades of work have explored how the time scales, constraints, and interactions of these forms of learning combine with different stimulus and response pairings and different combinations of reward and punishment. For example, we know that rewards are often better motivators than punishments, partly because they are more precise; you can simply reward the behavior you want, whereas with punishment you tend to punish getting caught, rather than accurately punishing the behavior you don't want.

This associative form of learning is basic to human nature, and its effects are widespread. If you reward your child by giving in after 20 minutes of nagging, is it surprising that this habit becomes common? If your manager punishes people who make mistakes, is it any wonder that people at work cover up their errors rather than admitting them? And if I've drunk a cup of coffee on a thousand previous occasions just before starting work, is it any wonder I feel a sense of contentment when sitting down to write with a steaming mug of the black stuff beside me and feel distress when I'm deprived of it? It may be arbitrary which mug I started drinking my coffee in, but now it has been wired into my brain via the reinforcing effects of caffeine. The coffee really does taste better when drunk from my favorite mug.

End Notes