Your brain can be tricked, and some of the best tricks are the unconscious kind that influence your thinking without you ever realizing it. A new little study of disgust, decisions and phantom confidence provides an excellent case in point.
The study design was simple but crafty. Participants watched a cloud of dots move in various directions on a computer screen and were asked to identify the main direction of the dots, and rate how confident they were in their decisions. At first the movements were easy to follow, then gradually became more complex.
Just before, the participants saw one of two faces flash on the screen, one with a neutral expression and the other with an expression of disgust. The faces appeared too quickly for conscious apprehension, and no one was told they'd seen them, but the participants’ bodies reacted nonetheless; the heart rates of those seeing the disgusted face increased and their pupils dilated.
Why the faces? Because the researchers wanted to find out if unconscious bodily reactions would influence how the groups handled the dots test—and they did. Those who saw the neutral face grew less confident as the movement of the dots became more complex. But when shown the disgusted face, the exact opposite happened: confidence in decisions made during the easier test weakened, while confidence in those made during the harder test increased.
Why the results played out this way is open to interpretation, but the research team thinks inducing unconscious disgust boosted alertness and sharpened focus, which made the participants at least feel more confident during the hardest parts of the test. In fact, the more their heart rates and pupils reacted, the bigger their confidence response. All of that confidence didn’t translate into greater accuracy, however, which wasn’t affected either way.
In evolutionary terms, disgust is a sign of danger, putting us on high alert even though we’re not thinking through the source of the danger. A similar effect unfolds in the famous “snake in the road” experiments, in which people react to an object on a roadway (a rope or bent branches) as if it’s a snake before they can consciously perceive what they’re reacting to. And that’s precisely the point—more often than we think, we’re reacting to factors around us without consciously engaging them.
Quoting the researchers from the study: "The results suggest that unconscious processes might exert a subtle influence on our conscious, reflective decisions, independently of the accuracy of the decisions themselves."
It’s likely no one in this study could rationally explain why they were or weren’t confident, and if they tried they’d create post-hoc explanations having nothing to do with the causes beyond their perception. Such is the human condition: we sound rational when asked to explain why we decided one way or another, even though the decision often emerges from an irrational stew.
The study was published in the journal eLife.
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