The Premack Principle, the relativity theory of reinforcement developed by psychologist David Premack in 1959, is arguably the most powerful tool you can employ when it comes to controlling your dog’s behavior. Terriers exemplify the need for such leverage, since they are hardwired to pursue their goals independently despite our wishes. If you don’t want to be left in the dust while your dog passionately follows her ambition down the street, you would be wise to learn about the Premack Principle.

The trick is to take the motivation that is distracting your dog and exploit it rather than compete with it. Otherwise, you will just get trumped by squirrels and loose dogs at the park as you fall entirely off of your dog’s radar. You will never take a natural motivation out of your dog. Instead, you need to answer it and exploit it. Punishing a drive only suppresses it and stores it for a later day. Put yourself in the middle of the equation, rather than outside of it, and show your dog how to get what she wants—by listening to you. Here is how this works:

You will require an apparently counterintuitive behavior (like coming) in order for your dog to get something that she wants (such as the squirrel). The idea you are teaching her is that she will fail to chase the squirrel if she pursues it on her own, but may successfully chase it if she goes through you first. To do this, you need to prevent her from chasing the squirrel against your wishes.

What you do: Use a long leash as you walk through the park every day. When she sees a squirrel, you give her only enough slack to watch the squirrel from across the way and to feel as if you are a distant thought on the end of the leash. From ten feet behind her, you simply say her name periodically, calling her to you without pulling the leash or admonishing her for ignoring you (which she totally will at first). You get no closer to the squirrel and no further, and neither does she.

After some time, unable to get closer to the squirrel, she will eventually come back to you in exasperation with your stubborn refusal to move. As soon as she does that, you say, “Yeah!!!” Then, gently—and very briefly—take her collar before saying “Okay!!!” and let it go, as you chase the squirrel across the park with her on the long leash. The take-home message for her is that coming to you resulted in squirrel chasing, while ignoring you totally failed. You showed her a new path from point A to point B—she must pass point C (you) first.