First impressions: never judge a book by its cover

Thomas Mussweiler offers practical advice to stop your unconscious biases affecting your interactions with other people


In 30 seconds:

  • Our first impressions of other people are long-lasting and highly consequential.
  • Be aware of how you come across in your first interactions with people and think about what you want to communicate to them.
  • Keep in mind that your first impressions of someone might be wrong and have no reflection on their trustworthiness or competence.

What the science says
Psychological research has produced fascinating insights into the dynamics and consequences of first impressions:

  • They are formed within seconds based on a range of cues.
  • This, in turn, can shape how that person interacts with you, creating a self-fulfilling prophecy dynamic.
  • They are long-lasting: the first impression you form of someone continues to have an effect on how you see them and feel about them over the longer term.
  • All of this happens regardless of whether first impressions are actually accurate or not.
  • They shape your actions and behaviours towards others.

The saying goes that first impressions count. And in fact, science shows this to be true. Psychological research reveals that the first impressions we form of someone go on to shape the way we continue to see them. They set the tone, as it were, for the relationship we’re likely to develop – and it happens remarkably fast. It takes us just 100 milliseconds to read someone’s facial features and form an opinion about them, and around five seconds to absorb information from other non-verbal cues, gestures and interactions.

In the age of Zoom and Teams, even the background context or environment in which we ‘meet’ someone for the first time contributes to the inferences we make about them.

This makes sense in evolutionary terms. We need to be able to form impressions of others fast to know how to react to or interact with them. There is huge adaptive value in being able to assess others as quickly as possible. Catching a glimpse of someone, however momentary, gives you a chance to make important inferences about them that tie to the key dimensions of social judgment: warmth and competence. Can we trust them? Are they friend or foe? Are they capable or incompetent? Can we depend on them?

The self-fulfilling prophecy

These judgments are fundamental to the way we function within groups or as a society, but what’s really telling about them is that the opinions formed are enduring.

Research has shown that first impressions predict the way we continue to think or feel about a person over time. In other words, that initial feeling or inference about someone tends to stick – almost no matter what. Even if they’re off base or partly inaccurate, first impressions really do matter because of the way they shape our ongoing perceptions.

Say you’re interviewing someone for a job. You want to know if they are competent and trustworthy – if they can be relied on to deliver in terms of the challenges of the role, or fit in with the company culture. Remember, your first impressions of that candidate are formed faster than you think. Within a few seconds you will make an assessment based on their facial features and non-verbal behaviour. You quickly form a rich opinion about what kind of person they are.

Now consider this. These impressions will shape the way you interact with this person, such that you end up drawing out the kinds of responses or reactions that confirm your first impressions.

Creating a dynamic

The research shows that a recruiter whose first impressions of a candidate are positive will create a process and environment that is warm and welcoming. The recruiter will ask more questions about the candidate’s strengths and competencies than about their weaknesses; they will likely talk more about the job than the candidate; and they will create a friendlier, more supportive dynamic because, to an extent, they have already decided that they want to ‘win’ this candidate for the role.

Conversely, if the recruiter forms a negative first impression, they will make it harder for the candidate to perform well. Questions will be tougher and more focused on the candidate’s weaknesses. This, in turn, will evoke different responses from the candidate – less confident, more defensive – that end up confirming your first sense of them and creating a sort of self-fulfilling prophecy dynamic that in reality may have little to do with the actual competencies and qualities of the interviewee.

So, first impressions are highly consequential. Positive or negative first impressions can bring out the behaviours we expect to see. They can set the tone for a relationship without us being aware of them, even if they are incorrect. And not only are first impressions often resistant to change, they are also a good predictor of the first impressions that other people will form of the same person. In other words, if you feel that someone is competent, chances are that others will feel the same.

This is particularly interesting in the political context. One study shows that the way people judge the competence of political candidates based on first impressions alone can predict with about 66% accuracy who will go on to win the election. So, making it into the UK Parliament, the US Senate, the German Bundestag and so on is arguably based on whether you appear competent or not. And that’s an important finding – because appearing competent and actually being competent are two different things.

Some key takeaways

Armed with these insights, what can you do to take control of the first-impressions process? We can break this down into two categories: the impressions you create in others, and those you form of other people.

1 The first impressions that you create in others
  • Be aware: Understand that the very first interactions you have with someone really matter and will have far-reaching consequences. Most of us are unaware of their importance. We tend to think that other people see us the way we see ourselves, but this is not necessarily the case. The way we think we come across might not be the way we are seen. Awareness of this is key. And remember, it’s not about whether these first impressions are an accurate impression of who you really are as a person – it’s about the consequences they have.
  • Take responsibility for managing these impressions: think about the peripheral cues that you give off and the environment in which you present yourself. Think about what it is that you want to communicate to others. If you are on a Zoom or Teams call, think about the background you choose. Think, too, about your facial cues. While our expressions can be hard to modulate, things such as posture and appearance can be practised.
  • Learn about the first impressions others form of you. And if you aren’t coming across the way you want, think about the cues that will help you do that and trigger the responses you want.
2 Forming first impressions of others
  • Be aware: Again, be aware that we all make fast judgments about other people’s trustworthiness and competence based on cues that might have nothing to do with their actual qualities. So, keep in mind that your first impressions might be wrong. If you are the recruiter, you want to hire someone who is actually competent and not someone who just looks the part.
  • Guard against stereotypes and biases: Remembering that we form impressions based on peripheral cues is crucial to staying mindful of the biases and preconceptions that we all hold, however subconsciously. Remember that your first impressions carry long-term and important consequences, so try to build that self-awareness and understanding to counter stereotypical thinking.

It’s only human to judge a book by its cover – but at least we can try to remember that it’s just the cover and not the contents.


Thomas Mussweiler is Professor of Organisational Behaviour at London Business School


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