Ever walked into a meeting and instantly liked someone before they said a word? Or found yourself doubting someone just based on a single trait, maybe their tone, the way they dress, or even one disagreement?
Those first impressions can feel like intuition… but more often than not, they are unconscious biases at work.
Welcome to the Halo and Horn effects – two sneaky but powerful mental shortcuts that influence how we judge others, often without realising it. For leaders, understanding these effects isn’t just helpful – it’s essential!
Because unchecked, they can quietly sabotage decisions, stifle talent, and erode trust.
The Halo Effect: When one positive trait outshines the rest
The Halo Effect is what happens when one great quality casts a golden glow over everything else.
The word “halo” is no accident. It comes from the religious iconography – the golden ring of light above the head of a saint. When we apply the halo effect, we are unconsciously elevating someone to “saint-like” status, assuming their goodness or competence in one area extends to all others.
Maybe someone is charismatic, stylish, or speaks with confidence. Suddenly, we start assuming they must also be smart, ethical, and highly-capable.
👩🏫 This bias was first spotlighted by psychologist Edward Thorndike in the 1920s. He discovered that when a soldier scored well in one area (e.g. physical appearance), they were also rated higher in totally unrelated areas like intelligence or leadership.
Our brains love shortcuts. So instead of doing the deeper thinking, we go: “If they are good at this, they must be good at that too.”
📌 Common Halo Effect Traps:
- In schools/universities: Attractive students (with similar performance) score higher grades.
- In the workplace: A confident speaker is assumed to be a strategic thinker.
- In boardrooms: One stellar presentation overshadows a year of inconsistent delivery.
- In marketing: A celebrity-endorsed product suddenly becomes more “trustworthy.”
This is not about bad intentions. It is about automatic processes. But unchecked? It distorts reality and limits our leadership potential.
“The eye sees only what the mind is prepared to comprehend.” ~ Robertson Davies
The Horn Effect: When one negative trait clouds the whole picture
If the halo effect wraps someone in a glow, the Horn Effect throws them into the shadows.
The term “horn” is derived from the devil’s horns – the symbolic opposite of a Saint’s halo. When you see one negative trait in someone, you might find yourself attributing other negative traits to them, even without any real basis.
Picture this: someone shows up late, seems distracted, or doesn’t respond how you expect. Before long, you are thinking: “They are unreliable… maybe even a poor fit.”
This, too, is bias. One perceived flaw (real or imagined) becomes the lens through which we judge everything else.
👩🏫 Thorndike spotted this too. In the same study, when a person scored low in one area (e.g. hygiene), they were marked down in other areas automatically.
📌 Common Horn Effect Traps:
- In hiring: A candidate’s weight, accent, or nervousness leads to assumptions about competence.
- In schools/universities: A quiet student is written off as disengaged, despite showing potential in other areas.
- In appraisals: One mistake overshadows months of meaningful contribution.
The horn effect is fast. It feels factual. But it’s flawed.
A Halo-and-Horn example in public life
Here’s a real-world case you may recognise – it was fast, “felt” factual, but flawed.
😇 For years, J.K. Rowling was seen through a classic halo effect. She wasn’t just the author of Harry Potter – she was admired for her philanthropy, especially through Lumos and her support for single parents.
👿When Rowling began voicing views around gender identity and women’s rights, particularly around the distinction between biological sex and gender identity, public opinion shifted rapidly. She was critical of people/groups that expanded the legal definition of “woman” to include self-identifying trans women. Critics labelled her transphobic.
Her books were boycotted. Her entire legacy was questioned. This is the horn effect in action.
One controversial stance coloured the public’s perception of her entire body of work. What was once admired became fuel for rejection.
📌This doesn’t mean people shouldn’t disagree with her. But it’s a reminder: We often move from one extreme perception to another – without nuance.
👩🏫We know how this turned out – The Scottish High Court (and subsequently the UK Supreme Court) ruled that the legal definition of “woman” in the Equality Act 2010 is based on biological sex at birth. But the horn effect has already caused a lot of damage.
What can we do about it?
Here’s the good news: while halo and horn effects are automatic, they are not unstoppable. You can lead differently.
Cultivate self-awareness
Ask yourself: “Am I reacting to this person’s actions… or my assumptions about them?”
Slow Down Your Judgement
Snap impressions are easy – but rarely complete.
Take time. Gather data. Look for patterns – NOT just one-off behaviours.
Use feedback loops
Bring in trusted voices. Ask others how they see a situation or an individual.
You cannot see the picture when you’re in the frame.
External perspective keeps you grounded.
Build bias-proof systems
Whether it’s hiring, feedback, or grading, structure matters.
Use checklists. Remove names. Get second opinions. And do NOT rely on ‘gut feel’ alone.
You can design around bias, starting today.
Final reflections
As leaders, we all have moments of unconscious bias. It doesn’t make you unkind – it makes you human.
But awareness? That’s where change begins.
So next time you feel drawn to someone instantly – or repelled without clear reason – pause and ask yourself: Am I seeing their full picture… or just their halo or horns?”
Because the most powerful leaders don’t just make smart decisions. They make fair ones.
And fairness builds trust. Trust builds teams. And teams? They change the world. 🌍
🎯 Call to Action:
✨ Take a moment this week to reflect on one recent decision you have made about a colleague, client, or team member. Could the halo or horn effect have influenced your thinking? What might you see differently if you paused, gathered more evidence, or sought an external perspective?
The best leaders don’t trust first impressions. They test them. Let this reflection be a step toward fairer, wiser leadership. 🌱
Impact Coaching & Mentoring (ICM) for Leaders 