How big is this spider in your eyes? New research finds people with a fear of spiders perceive the animals as being much bigger than they really are.
A fear of spiders, known as arachnophobia, is the third most common phobia in the US, affecting more than 30% of Americans.
While most people have a dislike of spiders, people with arachnophobia may be so fearful of the creatures that they experience intense anxiety, panic attacks, increased heart rate, increased blood pressure, fainting and even loss of bladder control.
Such a fear may stem from a negative childhood experience involving a spider, and some studies have suggested that because spiders posed a threat to our early ancestors, many of us have evolved to feel the need for a quick getaway when we see one.
Interestingly, previous studies have suggested that many humans have also evolved to perceive spiders to be significantly bigger than what they actually are - a phenomenon that further fuels our desire to run away in their presence.
In the journal Biological Psychology, Dr. Tali Leibovich, of Ben-Gurion University of the Negev in Israel, and colleagues set out to investigate this phenomenon further.
Overestimation of spider size driven by emotion
The team enrolled 27 female students to their study and asked them to complete a questionnaire to determine their fear of spiders.
Based on their results, the participants were allocated to one of two groups: those with a high fear of spiders and those with a low fear.
Next, the participants were shown pictures of insects and animals - including spiders, butterflies, wasps, rabbits, flies, birds and lambs - and were asked to estimate the "real world" size of the spiders relative to the other creatures. They were also asked to report how unpleasant each picture made them feel.
Unlike participants who had a low fear of spiders, those who had a high fear estimated the spiders to be significantly larger than other insects and animals; both groups similarly estimated the size of other creatures.
What is more, the researchers found that this overestimation of spider size was driven by both how unpleasant participants perceived the pictures to be and the relevance of the pictures; for example, though participants with a spider fear rated the pictures of wasps as highly unpleasant, they did not overestimate their size.
According to the team, their findings shed light on how our emotions influence our perceptions of the real world - in this case, size - and show how each of us experiences the world in a different way.
"To summarize, the current work demonstrates that size distortion is modulated by the relevance of the stimulus to the observer, as well as its aversive value. Thus, [...] we suggest that both valence and self-relevance play a role in size perception."
So, the next time your spider savior claims the eight-legged beast they are rescuing you from is "tiny," tell them that might be the case, but only in their eyes.
In December 2015, Medical News Today reported on a study that revealed how a 2-minute therapy could help cure the fear of spiders.