A primitive tribe called the Tasaday is discovered in 1971 in a remote mountain region of the Philippines. The tribe uses Stone Age tools and has no words in its language for “hate” or “war.”

Also that year:

• The 26th Amendment to the Constitution is ratified, lowering the voting age in all elections from 21 to 18.

• The U.S. Supreme Court rules that hiring policies must be the same for men and women.

• The longest trial in California history closes when Charles Manson and three of his female followers are convicted for first-degree murder in the slaying of Sharon Tate and six other people.

• Joe Frazier defeats Muhammad Ali to win the world heavyweight boxing championship. It is Ali’s first loss after 31 professional wins.