Where Did the Keys Go This Time?

You come through the door and take off your shoes. Your keys go... somewhere. You are already thinking about something else, so wherever they landed apparently wasn't important enough for your brain to record carefully. The next morning, you need them. They are not on the counter. They are not in your jacket. They are eventually discovered somewhere that makes you ask the completely reasonable question, “Why would I put them there?” Even more annoying, you don't remember doing it.

There is another version of this story. You come through the door. Shoes come off. Keys go on the hook. The next day, the same thing happens. Shoes off. Keys on hook. At first, you have to remember the second part.

That last detail matters because a habit isn't simply an action you repeat. Your brain learns to connect an action with something that regularly comes before it. That something is called a cue. In this case, taking off your shoes becomes the cue. you do that every time you come in the door, at least I do... The action attached to it is hanging up your keys. One happens, and your brain begins learning that the other should follow.

At first, the connection needs conscious thought. Shoes off. Oh right, keys. Put them on the hook. Your brain has to recognize the situation, remember the plan and deliberately carry it out. The next day, you do it again. And again. Each repetition gives your brain another opportunity to learn the connection between that cue and that action.

With repetition, the connection becomes increasingly well learned. Brain systems involved in learning actions and routines become hard-wired, familiar situation results in the familiar response. No energy attention thinking to make it happen. Eventually, shoes come off and your keys are heading toward the hook without an internal speech about proper key-storage procedures. Scientists call this increasing automaticity.

That is one of the great advantages of habits. Your brain has limited attention, and there are usually more important things competing for it than deciding where today's keys should live. Once a familiar cue can reliably get a familiar action started, less conscious effort is needed. Your attention is freed for whatever actually requires it. The brain has essentially turned a repeated decision into a well-learned route.

This does require one small thing: the cue needs to happen. If taking off your footwear is your cue, you had better actually be wearing footwear when you leave the house. Fortunately, during a Canadian winter, remembering shoes is rarely our biggest behavioural challenge. Shoes off → keys on hook is dependable because one event can become attached to the other.

Compare that with our first person, whose keys simply land wherever they land. There is still repeated behaviour, but there isn't a dependable shoes off → keys on hook connection. Tomorrow morning, the brain has no automatic key-hanging routine to thank for solving the problem. Instead, it gets the much more exciting assignment of reconstructing yesterday's movements while somebody announces, “I KNOW I put them somewhere.” This is almost the opposite of a useful habit: very little attention invested when the keys are dropped, followed by considerably more attention when they need to be found.

So repetition helps explain how habits become automatic. But it doesn't explain everything. Some behaviours also produce outcomes that make us particularly interested in doing them again. Check a notification and there might be a funny message. Open a game and something enjoyable happens immediately. Your brain learns from those outcomes too.

A brain chemical called dopamine is important in this learning. Dopamine helps brain systems learn about rewarding or important outcomes and the cues and actions connected with them. If something desirable follows a behaviour, that can strengthen learning that makes the behaviour worth repeating. Over time, the cue itself can become increasingly important because the brain has learned what it predicts. Now we have more than repetition. We have a cue, an action and an outcome the brain has learned matters.

Some substances can make this process much more powerful and much more serious. Addictive drugs can strongly affect dopamine and other brain systems involved in reward, motivation and learning. Their effects can strongly reinforce substance-taking behaviour. With repeated use, places, people, objects, situations or even feelings associated with using a substance can also become learned cues. Those cues may eventually trigger powerful urges to use.

But addiction is not simply a really bad habit. That distinction matters. Habit learning can be part of addiction, but addiction can also involve major changes in motivation and behaviour, intense craving, impaired control and, with some substances and patterns of use, physical dependence and withdrawal. A person may eventually use a substance not only because its effects were once rewarding, but also because using relieves something intensely unpleasant. Calling all of that a “bad habit” badly underestimates what may be happening.

The keys give us the simpler version of the same important idea about learning. Look for what happens first. A cue and an action repeatedly paired together can become so well learned that the cue starts getting the action moving with much less conscious thought. Reward can make some repeated behaviours even more compelling by helping the brain learn that what follows is worth pursuing again.

That is why a habit has more of a story than it first appears. There is the cue, the action attached to it, repetition and the brain gradually needing less conscious thought to get the action started. Sometimes there is also a rewarding outcome strengthening the learning.

So tomorrow morning, if someone is wandering through the house asking how their keys could possibly have disappeared again, the keys probably haven't developed a plan.

The brain just never learned where to send them.