15% of the population have Left-Right Confusion

As much as 15 percent of the population may have difficulty distinguishing left from right according to a new study. Left-right confusion in otherwise healthy sapiens was explored using 3 experiments in The Netherlands.

In one experiment (N = 404), Ineke van der Ham et al. asked participants to rate their own Left-Right Identification (LRI) skills on a ten-point scale. The 10-point scales ranged from 1 (very poor/slow) to 10 (perfect performance/fast). 59 out of 404 (14.6%) participants rated themselves as a 5 or lower for “how well they could identify left and right”.

While the majority of participants said they could instantly tell left and right because they “simply knew”, 42.9 % of the participants said they consulted their hands for help. Some used specialized strategies such as holding the thumb and index finger in a 90° angle to assess whether this forms the letter “L” (for left) or a mirror image of “L”.

In another experiment, the researchers measured how fast people (N = 229) could name the highlighted arm (left or right) in a human figure stimuli. Reaction times, which yielded an objective measure of LRI ability, was found to be greater when the human figure on the screen was spatially aligned to the participant. These alignment effects were strongest in people who used hand-related strategies.

"Both alignment in side (facing the stimuli’s backside) and congruency in hand position increased performance."

In yet another experiment, the researchers investigated if and how people (N = 99) mentally align their own body to the stimuli. Specifically, they tested whether the perceived image of one's hands were consulted during the process. To test this, the hand identification task from experiment 2 was done with the participant’s hands crossed or hidden from view. The modification had no effect on performance, indicating, according to the authors that participants consult a "stored stable spatial representation of their body”.

The findings suggest, Dr. Ineke told Sapien Journal, that people with persistent Left-Right Confusion may have spatially weaker/less defined body representation, so it does not help them as much in determining left and right. This makes them more inclined to use alternative body-based strategies.

Read more about the study here.