Understanding First Impressions: The Science Behind Instant Judgement
- Melissa Hughes
- May 1
- 3 min read
Updated: Jul 1
The Power of First Impressions
You know the feeling. You meet someone and immediately get that gut reaction—something’s off. You don’t trust them. You don’t like them. You don’t know why.
Spoiler alert: It’s not just intuition. It's neuroscience!
With every new encounter, you form an immediate impression of another person, and vice versa. These first impressions are powerful forces that set the tone for that exchange and determine the quality of the relationship moving forward.
In less than a tenth of a second, your brain processes a wealth of information, piecing together emotional memories, past experiences, and personal values. As a result, you form a judgement about that person based on your initial feelings and biases.
The Speed of Judgement
In just 100 milliseconds—about the time it takes to blink—you can determine whether you like or dislike someone you’ve just met. Studies have shown this astonishing speed. It's a testament to how quickly our brains can work.
But what happens in that brief moment? Your brain utilizes mental shortcuts called heuristics. These shortcuts help expedite decision-making. However, they are not always accurate. We tend to “thin slice,” meaning we make broad assumptions based on minimal data.
Moreover, confirmation bias plays a significant role in shaping our perceptions. This cognitive bias leads us to notice and prioritize information that supports our initial impressions, ignoring the rest. For instance, if someone appears standoffish, our minds actively gather more reasons to justify that feeling.
Not only faces influence our perceptions. Tone of voice, posture, clothing, eye contact, and even micro-expressions all contribute to our initial impressions, processed at lightning speed.
Emotional Memory: A Crucial Component
When we meet someone new, our brains draw on previous emotional memories. This allows us to rapidly assess not just the person before us but also how they might fit into our past experiences. Your brain is always searching for patterns. If a person’s demeanor resembles someone who has hurt you before, your defense mechanisms may kick in.
It’s crucial to recognize that these instincts are not inherently good or bad—they are natural responses informed by our pasts. Understanding this can help you control your reactions more effectively.
The Impact of Physical Characteristics
Physical characteristics significantly influence that split-second judgement. Traits like piercings, hair color, tattoos, and even clothing can sway our initial thoughts about someone. Research shows that people who smile are perceived as more attractive.
These impressions boil down largely to two factors: friend-or-foe and powerful-or-not. Judgements of trustworthiness and power shape our perceptions, focusing on our assumptions about another person’s intentions towards us.
Research Insights
Princeton psychology professor Alexander Todorov is leading investigations into how appearance impacts social evaluations. He found that candidates perceived as more competent often won elections merely based on their looks.
Interestingly, studies reveal that even as young as seven months old, infants exhibit gut feelings about trustworthiness similar to adults. Additionally, researchers discovered a simple increase or decrease in skin brightness significantly alters impressions. Brighter faces tend to be seen as more trustworthy, while changes in this "reflectance" can shift perceptions of masculine or feminine traits.
The Influence of Media on First Impressions
In our digital age, media can also affect how we form first impressions. Other studies indicate that frequent media multitaskers might be more easily distracted by irrelevant stimuli when making judgments about unfamiliar people. This suggests that multitasking can weaken our focus and lead to less accurate character assessments based on appearances.
The Cost of a Bad First Impression
Here’s the kicker: once a negative impression is formed, it’s hard to undo. Studies show that even when new, positive information is presented, people often cling to their initial gut feelings. This is because our brains prefer consistency over revision.
It requires more cognitive effort to change an opinion than to maintain one. In fields like hospitality, leadership, or sales, understanding this principle is crucial. In those first few moments, you are either winning or losing.
Being Authentic
Understanding that first impressions can deeply affect interactions does not mean you should be disingenuous. Instead, it’s about awareness. Recognizing the brain’s default settings can empower you to:
Show up with intentional energy.
Signal trust through your posture, eye contact, and tone.
Catch yourself when jumping to conclusions about others.
Give people grace to defy your expectations.
While we cannot control our immediate reactions, we can choose how we respond next.
