For all the advances made in neuroscience, we still don’t fully understand how our brains respond to other people. What we do know is that it’s complex.

Join the Chorus

Recent studies, including this one from Rochester University, are showing that when we see someone we recognize, the brain responds with a chorus of neuronal activity. Neurons from different parts of the brain fire in unison, creating a congruent response that may simultaneously pull from memory, from emotion, from the rational regions of our prefrontal cortex and from other deep-seated areas of our brain. The firing of any one neuron may be relatively subtle, but together this chorus of neurons can create a powerful response to a person. This cognitive choir represents our total comprehension of an individual.

Non-Verbal Communication

“You’ll have your looks, your pretty face. – And don’t underestimate the importance of body language!” – Ursula, The Little Mermaid

Given that we respond to people with different parts of the brain, it makes sense that we use part of the brain we didn’t realize when communicating with someone else. In 1967, psychologist Albert Mehrabian attempted to pin this down with some actual numbers, publishing a paper in which he put forth what became known as Mehrabian’s Rule: 7% of communication is verbal, 38% is tone of voice and 55% is body language.

Like many oft-quoted rules, this one is typically mis-quoted. It’s not that words are not important when we communication something. Words convey the message. But it’s the non-verbal part that determines how we interpret the message – and whether we trust it or not.

Folk wisdom has told us, “Your mouth is telling me one thing, but your eyes are telling me another.” In this case, folk wisdom is right. We evolved to respond to another person with our whole bodies, with our brains playing the part of conductor. Maybe the numbers don’t exactly add up to Mehrabian’s neat and tidy ratio, but the importance of non-verbal communication is undeniable. We intuitively pick up incredibly subtle hints: a slight tremor in the voice, a bead of sweat on the forehead, a slight turn down of one corner of the mouth, perhaps a foot tapping or a finger trembling, a split-second darting of the eye. All this is subconsciously monitored, fed to the brain and orchestrated into a judgment about a person and what they’re trying to tell us. This is how we evolved to judge whether we should build trust or lose it.

Face to Face vs Face to Screen

Now, we get to the question you knew was coming, “What happens when we have to make these decisions about someone else through a screen rather than face to face?”

Given that we don’t fully understand how the brain responds to people yet, it’s hard to say how much of our ability to judge whether we should convey trust or withhold it is impaired by screen-to-screen communication. My guess is that the impairment is significant, probably well over 50%. It’s difficult to test this in a laboratory setting, given that it generally requires some type of neuroimaging, such as an fMRI scanner. In order to present a stimulus for the brain to respond to when the subject is strapped in, a screen is really the only option. But common sense tells me – given the sophisticated and orchestrated nature of our brain’s social responses – that a lot is lost in translation from a real-world encounter to a screen recording.

New Faces vs Old Ones

If we think of how our brains respond to faces, we realize that in today’s world, a lot of our social judgements are increasing made without face-to-face encounters. In a case where we know someone, we will pull forward a snapshot of our entire history with that person. The current communication is just another data point in a rich collection of interpersonal experience. One would think that would substantially increase our odds of making a valid judgement.

But what if we must make a judgement on someone we’ve never met before, and have only seen through a screen; be it a TikTok post, an Instagram Reel, a YouTube video or a Facebook Post? What if we have to decide whether to believe an influencer when making an important life decision? Are we willing to rely on a fraction of our brain’s capacity when deciding whether to place trust in someone we’ve never met?