Do you stick your tongue out or scowl when you concentrate? Maybe, like one of our listeners, you screw up your face when you’re playing music. Do these facial expressions actually help with the task in hand? And could they hold clues to humans’ evolutionary past?

In this edition of CrowdScience we tackle the science of face-pulling, along with several more burning science questions sent in from listeners around the world. We explore why it’s almost impossible to talk without moving your hands; and why bilingual people often switch to the first language they learned when they’re counting, even if they speak another language the rest of the time.

Presented by Anand Jagatia and Marnie Chesterton

Produced by Cathy Edwards

(Photo: A boy sits at a table, looking down in concentration as he draws in a note pad. Credit: Getty Images)