Why a Yawn Spreads: teacher key

Hiccups, Sneezes and Yawns, grade 10 edition, written for 10th grade. Yawns are catching, even from a thought or a sound, and scientists have tested why. Their clues come from temperature, from empathy and from the nerves that run the reflexes.

Read the book. Print this page for the key.

Questions and answers

1. When does contagious yawning fully show up in children?
   • Before birth
   • About age four or five (answer)
   • Only in adults
2. Who are we much more likely to catch a yawn from?
   • A close loved one (answer)
   • A stranger
   • A person far away
3. What did the Vienna team find about temperature and contagious yawning?
   • It happened most near freezing
   • It happened most at 37 C
   • It was limited to a range of temperatures around 20 C (answer)
4. What may explain why newborns and infants yawn often?
   • Their frequent switches between sleeping and waking (answer)
   • Their need for more oxygen
   • Their very warm rooms
5. Which part of the brain starts a yawn, with the brainstem?
   • The ear
   • The hypothalamus (answer)
   • The diaphragm
6. What does contagious mean in contagious yawning?
   • Very slow
   • Painful
   • Spreading from one to another (answer)

Words

• contagious: spreading to others
• empathy: sharing feelings
• ultrasound: body scan
• neurotransmitters: brain messengers
• glottis: throat gap