Sometimes, there's just a feeling.
You're looking at someone, listening to them, and thinking: "Something here's not quite right. He's full of it, isn't he?"
Times when this feeling is especially strong include: listening to your boss, being on a first date, encountering a sales person from an insurance company, or witnessing Mark Zuckerberg or Larry Page talk about privacy.
Science has long wondered whether there might be an unconscious formula for spotting a liar.
So some researchers at the Haas School of Business at the University of California, Berkeley, thought they'd see whether there was something better than rational processes to determine a liar's tics and tendencies.
As the Association for Psychological Sciences reports, it's long been known that thinking your way to discerning a liar is a road to failure.
Study author Leanne ten Brinke told the APS: "Our research was prompted by the puzzling but consistent finding that humans are very poor lie detectors, performing at only about 54 percent accuracy in traditional lie detection tasks."
We are, in essence, dupes ready for the taking, naive lambs ready to be slaughtered by misstatements; kind, lying eyes; and smiles that are a thin disguise.
In this experiment, 72 people were asked to watch an interview with someone who may or may not have been a criminal. Some had actually stolen $100 from a bookshelf.
The guinea pigs were first asked which of these potential criminals had been lying and which had not. The answers were disappointing. A mere 43 percent spotted a liar; 48 percent managed to identify a truther.
However, the researchers weren't going to take rational responses for an answer. So they had the intrepid 72 hooked up to be measured on their instinctive reactions. Here, there was much more instant correlation between unconscious reactions and liars (and truth-tellers).
Having performed a further experiment, Ten Brinke concluded: "These results provide a new lens through which to examine social perception, and suggest that -- at least in terms of detection of lies -- unconscious measures may provide additional insight into interpersonal accuracy."
The question remains, however, as to how often we accept the word of our unconscious and how often we still insist on giving liars the benefit of too much doubt.
Are we, in truth, excessively disposed to being naive? Or is it that liars are usually telling us things we wish were true? The latter seems to be the case in all matters of love, for example.
We want people to love us, so when they tell us they do, we ignore the impulses that insist: "He's wearing a wedding ring and has two separate cell phones! Run!" or "She was still living with her drug-dealer boyfriend when she told you she loved you! Hide!"
There is one very uplifting conclusion from this academic work.
All those detectives in novels who ramble about the case seeking inspiration for the murderer's name are clearly attuned to the powers of truth.
Fine characters such as the great Inspector Montalbano, Inspector Morse, Inspector Lewis, Hercule Poirot, Aurelio Zen, and Inspector Singh spend whole books trying to ensure they aren't suckered by their rational minds.
In an era where rationality is attempting a military coup of our beings and behaviors, it's as well to consider that our only freedom and good judgment lies in our unconscious.