My first book Changing on the Job,  addresses a question clients often ask me about – how to support their teams to improve. The answer I give them is that a huge factor in whether people can improve at work is whether their leaders are expanders or compressors.

You’ll probably recognise this distinction. Expanding leaders push you to be better than you knew you could be, urge you to take on new challenges, and then support you if you fall down because the challenge was slightly bigger than you were ready to handle. You think more clearly in their presence, and you find yourself filled with possibilities because their perspective adds to and expands yours. These leaders make you bigger.

Compressing leaders, on the other hand, make you smaller. In their company you stumble around for words and ideas that you felt secure about just minutes before. Your ideas get more conventional, less creative. The critical voice in your head eliminates most ideas before they even leave your mouth. You kick yourself afterwards for being so anxious, and you believe there must be something wrong with you.

Turns out though, there’s something wrong with compressing leaders. Ideally leaders create the context for us to be at our best. The Expanders are actually keeping the right balance of challenge and support and leading you to a better place; the Compressors have the balance wrong and are just leading you to wish for a new job.

The good news is that leaders aren’t born one way or the other; in fact, we’re all likely to have both of these inside us. The question is more about which one shows up more often. The answer to that has as much to do with your old habits and what you choose to be than your DNA. If you’re wanting to spend more time expanding and less time compressing, it takes some focused attention.

The first important step is just noticing the difference between these two kinds of leaders and watching yourself to see which one shows up when you open your mouth. Compressors have no patience for emotion or error—in themselves or others—and so they miss out on much of the greatness of our humanity as they try to deny some of the frailties. This makes them quick to criticize and slow to apologise. Expanders remember to ask questions rather than make judgements, seek to understand the perspective of others before pressing their own points, give and receive all kinds of feedback. Anyone can learn to do that. And the benefits are expansive too. As you practice these expanding skills more and more, your people grow before your eyes, becoming more creative, more capable, more alive than they were before. Their expansions create more space for you, creating a virtuous cycle that creates a workplace where everyone can change on the job.