The Dangers of Assuming

Why we assume, how it harms us — and how to become more mindful of assumptions

Sally Clarke
4 min readFeb 13


Azerbaijan, 2018.

As humans and as leaders we constantly make assumptions: we draw on our past experiences to find patterns in how the world works.

Susan David refers to our mind as a meaning-making machine. Our minds use assumptions to make sense of the billions of bits of stimuli and sensory information we are bombarded with every day.

Assumptions save our brains the hassle and energy of analyzing each situation completely anew. They help us navigate many of the repetitive components of modern life.

However, many of the assumptions we make can harm our communication and our relationships, as leaders and as humans.

“The most misleading assumptions are the ones you don’t even know you’re making.” — Douglas Adams

A comforting (but false) story we tell ourselves

Assumptions are based on past experience, and have the task of protecting us from further harm. As Brené Brown explains, when something difficult happens — your partner is cold or distant, someone cuts you off in traffic, a colleague seems dismissive during a meeting — your brain begs you for a story to explain what is happening.

When you give it a story, it rewards you with calm and reduces your stress response. At some subconscious level, you think: “Oh, yeah, now it makes sense”.

They are angry at me. I must have done something wrong.

He could have sideswiped me, what an asshole.

They don’t think I’m competent. I should shut up.

However, the brain is so set on removing the ambiguity and uncertainty you’re facing that it will reward you with this sense of calm regardless of the accuracy of the story. Because these assumptions calm our brain and reduce our stress response, we take them to be true irrespective of whether they are or not.

We don’t query or investigate further, as we’ve already had the physiological payoff of an explanation (even if it’s total BS).



Sally Clarke

Co Director of Human Leaders. Wellbeing & burnout author, expert, coach, writer & speaker. Global adventurer. she/her