and his shirt is covered in, well, cheese. If you find yourself smiling too, it’s not

his charm.

We mimic each other’s facial expressions, posture and elements of speech all the time;

mostly without actually realising it.

Back in 1992, researchers looked at the activity of single neurons in the brain of the macaque

monkey. They came across a system of neurons that fired both when the monkey performed

an action - grabbing a peanut - and when the monkey observed a researcher grabbing a peanut

too.

The researchers called the system “mirror neurons” because the neurons “reflected"

a behaviour; even though the monkeys weren’t performing that behaviour themselves. And

“mirror neurons” aren’t just a monkey thing, there’s evidence for the system in

human brains too.

In one study, human participants were shown a face with either a happy, angry or neutral

expression... but only for 30 milliseconds. The expressive faces weren’t on the screen

long enough for the participants to notice, so they had no idea that they were being subconsciously

exposed to them.

Still, the participants who were shown the happy face had increased electrical activity

in the muscles needed to smile, and mimic that face. And those shown the angry face

initiated the muscles needed to mimic the angry expression.

It’s thought that we mirror behaviours and facial expressions to help us understand the

emotional states of others and learn by imitation. In another study, researchers impaired the

participants ability to mimic faces by having them chew gum, or hold a pencil in between

their teeth. Their ability to recognize some emotional expressions, like happiness, was

impaired too. So this mirror neuron system isn’t only connected to our movements, it

may also be connected to our feelings.

In a recent study, participants were shown videos of a hand in either visibly cold or

visibly warm water. While watching the cold water video, the participants’ hands dropped

in temperature. Researchers dubbed this “temperature contagion.”

The drop in temperature was more noticeable in participants who reported having higher

levels of empathy, but we can't say if this was caused by mirror neurons or not. Some

neuroscientists are skeptical of the mirror neuron theory and say it’s been over generalised.

While research into our neurons role in imitation is ongoing, we do know that we’re primed

to mimic what we observe - from cracking a smile to the point where we can “catch a

cold” without actually experiencing a change in temperature.

It really is a case of monkey see, monkey do.

And if you don’t already, subscribe to BrainCraft! I have a new episode out every Thursday.