Your Eyes Are Saying More Than You Think

What research into pupils, trust and first impressions taught me about portrait photography

Back in 2018, I wrote an article after stumbling across a piece of research that completely fascinated me. Researchers had discovered a connection between our pupils and trust, finding that people were more likely to trust virtual partners whose pupils were dilating than those whose pupils were constricting. Even more fascinatingly, the participants' own pupils began to mimic the changes they were seeing in the other person's eyes.

At the time I was photographing people every day and spending an enormous amount of time studying faces, expressions and body language, so naturally I disappeared down the rabbit hole. Eight years later, while going through some of my old writing, I found that article again and wondered what had happened to the research since.

It turns out the story has become considerably more interesting.

The eyes really do matter

Further research published in 2019 looked again at the relationship between pupil size, trust and reciprocity. Across three experiments, people trusted partners with dilating pupils more than those with constricting pupils and attributed more positive characteristics to them, including friendliness, attractiveness and trustworthiness. In another experiment, people were more likely to reciprocate financially towards someone whose pupils were dilating.

Then I found a 2022 study that interested me even more. Researchers investigated what happened when people weren't consciously aware of the facial information they were being shown and found that while facial expressions influenced trust when people could consciously perceive them, pupil size appeared capable of influencing trust even when the eye stimulus was outside conscious awareness. The researchers were cautious about the findings and called for further replication, but I find the possibility fascinating.

We may be responding to extraordinarily small signals in another person's face without having any idea that we're doing it, and as someone who has spent more than 20 years watching people through a camera, that really caught my attention.

Not because I've suddenly discovered a secret lighting formula for making executives look trustworthy, I haven't, and I certainly wouldn't suggest we start artificially engineering people's pupils for their LinkedIn photographs. What interests me is what this tells us about how much communication can be happening inside a photograph before we've consciously decided what we think of the person in it.

We are constantly reading faces

When you look at someone's portrait, you aren't simply registering their hair, clothes, age or expression, you're reading them and you're doing it remarkably quickly. Somewhere in the background your brain is picking up information and beginning to form an impression. Does this person appear confident, approachable, comfortable, guarded, engaged, warm or nervous? You probably aren't consciously running through a checklist, you simply get a feeling.

Some of that judgement will be accurate and some of it won't. A photograph can never tell us if somebody is genuinely trustworthy, competent or a good leader, and I think we need to be very careful about pretending it can, but photographs absolutely influence perception and that distinction matters.

Another piece of research published in 2022 involved more than 4,500 participants across 32 countries. Researchers showed people complete faces as well as isolated areas of faces and asked them to make judgements about trustworthiness. The eyes and eyebrows emerged as the most informative region and people's trustworthiness ratings based on the eye region alone were remarkably similar to their ratings when looking at the complete face.

I love this because it puts some science around something photographers and portrait painters have understood instinctively for a very long time. The eyes matter, but I don't think it's simply about making sure they're sharp, beautifully lit and looking directly into the camera, I'm much more interested in what is happening behind them.

I can see when someone isn't comfortable

I've photographed thousands of people over the years and experience teaches you to notice very small changes. Someone walks in holding their shoulders slightly too high, their smile appears before their eyes join in, their hands are tense or they're concentrating so hard on being photographed that I can almost see them thinking about every part of their face.

Technically, I can take the photograph, but it isn't the photograph I want.

So we talk, I adjust something, move them, give them something to do or sometimes make them laugh. Other times I simply stop talking and give them a moment. Eventually something changes, the shoulders drop, the expression becomes less deliberate and their attention moves away from what am I supposed to be doing? and suddenly I have more of the person and less of the pose.

Those changes can be tiny, but the camera sees them and apparently, so do we.

You can't direct authenticity

We talk a lot about authenticity in personal branding and executive presence, but authenticity isn't an expression I can simply ask somebody to put on for the camera. Telling someone to "look natural" or "relax" rarely produces either of those things.

My job is to create the conditions where I can see more of the person who is actually there and that's a very different thing.

It's also one of the reasons I've become increasingly interested in photographing leaders beyond the traditional controlled portrait. When somebody is listening, thinking, talking to their people or concentrating on something other than my camera, I start seeing different information. Their expressions change, their body language changes and their eyes change, and the photograph becomes less about performing leadership for me and more about allowing me to observe it.

And then AI arrived

When I originally wrote about pupil dilation and trust in 2018, AI-generated professional imagery wasn't part of the conversation. Today it very much is and we can now generate extraordinarily polished faces, alter expressions, replace backgrounds, smooth skin, change clothing and even create people who never stood in front of a camera at all.

That makes all of these tiny human signals even more interesting to me.

The slight asymmetry of an expression, the way someone's eyes change when they're genuinely amused, the concentration on their face when they're listening or that fleeting expression between one pose and another are not imperfections I want to remove. Increasingly, they're the things I'm looking for because they give us something polished imagery alone can't necessarily provide, a sense of the actual person.

This connects very closely with something I've been thinking and writing about recently around the changing CEO profile in the age of AI. As technology becomes increasingly capable of manufacturing the polished parts of professional communication, perhaps the genuinely human parts become even more valuable.

Trust isn't something I can photograph

There is an important line here because I cannot take a photograph that proves someone is trustworthy and no photographer can. Trust is earned through behaviour, actions, consistency and experience over time, and we should be particularly cautious about judging someone's character from their facial appearance alone because human perception comes with all sorts of assumptions and biases.

What photography can do is create an introduction.

Before someone hears you speak, sits across a boardroom table from you, watches you lead a room or works alongside you, they may encounter your photograph and in that moment an extraordinary amount of visual information is being processed. Some of it consciously and, according to some of this research, perhaps some of it without us even knowing.

That's what continues to fascinate me.

Eight years ago I wondered if understanding things like pupil dilation was somehow a form of trickery. I don't see it that way anymore, I'm much more interested in what the research tells us about people and how incredibly perceptive we are as social creatures. We notice things we don't realise we're noticing and respond to eyes, expressions, posture, movement and hundreds of other tiny signals that together begin to form our impression of another human being.

That makes my job considerably more interesting than simply making somebody look good. I'm watching, waiting and looking for the point where the person stops thinking quite so much about being photographed and something more natural takes its place, because perhaps some of the smallest things happening in a portrait are doing far more of the communicating than we realise.

After more than 20 years behind the camera, I think that's where some of the most interesting photographs begin.