The Window of Tolerance: Why Good Leaders Sometimes Lose Control
It has happened to me more than once. I had slept only four or five hours. My day started with an 8 a.m. call. The Tube was delayed for what felt like an eternity, and I arrived at the office just in time to switch on my computer. My inbox was already full of escalations. The day became a succession of crises and difficult conversations. By four o'clock, my nerves were razor-thin.
When one of my team members questioned a decision I had made, I snapped. She would probably say I exploded. She was in tears, and I was left wondering what had just happened. I apologised immediately.
Why do perfectly kind and caring leaders sometimes lose control? Why do composed colleagues suddenly burst into tears? Why do intelligent, thoughtful people become defensive, impatient or unusually certain of their own position? The answer often lies less in personality than in the way our nervous system responds to stress.
Although the brain distinguishes between physical and social threats, many social experiences—rejection, humiliation, exclusion, uncertainty, conflict and loss of status—activate overlapping neural systems involved in detecting danger and preparing us to respond. From the perspective of our nervous system, social survival and physical survival are deeply intertwined. For this reason, our nervous system is constantly scanning the environment for signs of safety or danger.
When we feel safe, we remain within what psychologists call our Window of Tolerance. Within this window, we can think clearly, regulate our emotions, tolerate ambiguity, remain curious and collaborate effectively. We are able to hold different perspectives without immediately needing to defend our own.
When our nervous system detects threat, however, we begin to move outside this window. This is especially likely when our capacity for self-regulation has already been depleted by fatigue, pressure or prolonged stress.
Fight, flight, freeze responses begin to emerge—not because we consciously choose them, but because our biology prioritises protection over reflection. Our thinking becomes narrower. We become more reactive, less curious and more convinced that our own perspective is the correct one. What feels like clear judgement is often a nervous system trying to restore a sense of safety.
Organisations often interpret these moments as failures of professionalism, emotional intelligence or character. Sometimes they are. But surprisingly often they are failures of regulation.
The best leaders are not those who never leave their Window of Tolerance. They are the ones who recognise it sooner. They notice when their thinking becomes rigid, when their patience disappears or when they feel compelled to win rather than understand. They know that, in those moments, stepping away for ten minutes may be a wiser leadership decision than continuing the conversation.
In my experience, emotional outbursts cannot simply be tidied away afterwards. Even sincere apologies do not fully repair the trust or psychological safety that may have been lost.
In the moment, body awareness, slowing the breath, taking a short walk or postponing a difficult conversation can all help. But the deeper work happens long before the crisis. It lies in building a life that allows us to remain within our Window of Tolerance more often: getting enough sleep, establishing healthy boundaries, learning to say no, creating space for recovery and recognising when we are asking too much of ourselves.
We invest enormous effort in developing leaders through strategy, communication and decision-making training.
Perhaps one of the most fundamental leadership capabilities is even simpler: Knowing when your nervous system has taken over your judgement.
Because once we leave our Window of Tolerance, we are no longer responding only to the situation in front of us. We are also responding to our biology.