Popular depictions of body language often focus on the ability to decode lying, or scanning someone to detect defensiveness, or other such negative behavior.  The idea is that people may say one thing and be signaling another, so body language is a useful way to find out the truth.

This way of using body language often seizes on particular ‘tells’ – gestures that reveal the truth – that by implication are universal, or near-universal.  One of those is blinking.  The idea is that blinking faster indicates a potential fib.

So, is blink rate a reliable indicator of how likely the person is to be telling the truth or not?  What does the research show?

Researchers studied contestants on a TV quiz show and reported on the results in 2023.  These demonstrate beautifully the danger in thinking about specific physical responses as ‘tells,’ or indicators of a particular thought or intent.  First of all, people do blink faster under stress.  But that simply indicates a stress response, not a declaration of the intent behind the stress.  In other words, you might be stressed because you’re trying to recall the truth, or a lie, or the right answer, or a host of other things.  Stress is a response to certain conditions.  As such, your stress may be someone else’s catnip.  And you may be stressed about lying – or the truth.

Moreover, it turns out that blinking also slows when you are thinking hard and can speed up when you are signaling that you are hearing a question or getting ready to give an answer.  In other words, it’s a signal of a response to external stimuli, not a clear indicator of your intent to tell the truth or to lie.

In this way, blinking is like so many other individual bits of body language – it is multi-determined.  A clumsy phrase that simply means that it can have many reasons lurking behind it.  We may cross our arms because we’re defensive – or because we’re tired, cold, or ready to quit.  Or because we’re making ourselves comfortable for a long session of playing the dummy in a game of contract bridge.

Don’t look to body language for ‘tells’.  Look to body language (in the workplace) for answers to certain basic questions, such as, “Is the person sitting in front of me open or resistant to the idea I’ve been selling him on for the last 45 minutes?” “Is this person a friend or a foe?”  “Is this person on our team or looking to switch sides?” Those are the sorts of questions that body language can usefully answer; those are the questions that are fair to expect reliable answers for.

And in more intimate relationships in the workplace or beyond, most humans are reasonably good at reading the signals of people that they know well – long-time colleagues, friends, family – especially when they are moved by a strong emotion.  So, for example, when your spouse runs into the house excited about a raise, you can reliably pick up that something (good) is going on.  That’s because you know how that person normally acts, and thus spotting a variation from the norm is relatively easy and reliable.

Rather than trying to catalogue a list of tells, then, seek to understand people in your world by paying attention to both what they say and how they say it.  Over time, you can become a reliable reader of body language of the people you live and work with.  It’s simply good listening.