Simplify the following text for a Grade 10 native English-speaking person.
Original: Timothy Francis Leary ( October 22 , 1920 -- May 31 , 1996 ) was a highly influential American psychologist and writer , known in later life for advocating advanced research into the therapeutic benefits of psychedelic drugs .
Simplified: Timothy Francis Leary , ( October 22 , 1920 -- May 31 , 1996 ) was an American writer and psychologist .