Layers of Friends: teacher key

Friendship, grade 12 edition, written for 12th grade and up. Friends come in layers of about 5, 15, 50 and 150. Studies of phone calls, baboons, apes and Harvard's long run add what is known and what is not.

Read the book. Print this page for the key.

Questions and answers

1. How many people are in the closest circle of friends?
   • About 15
   • About 5 (answer)
   • About 50
2. How many hours of observation was the chimpanzee study based on?
   • 355
   • 1,500
   • 78,000 (answer)
3. What did the researchers say the similar patterns in apes and people reveal?
   • Deep evolutionary continuity in how complex societies are organized (answer)
   • That apes copy people
   • That friendship is rare
4. Why does the baboon research stop short of saying friends cause longer lives?
   • They had no data
   • The researchers were not sure exactly how close relationships lead baboons to live longer (answer)
   • Baboons live in small groups
5. What does embedded mean in the page about moving?
   • Hidden
   • Angry
   • Settled in (answer)

Words

• continuity: unbroken thread
• introverts: quiet people
• embedded: settled in
• grooming: cleaning each other
• correlated: linked together