A known peacenik Vaughn was apparently a fine scholar.. "He started off studying to be a journalist but quit after 12 months and moved with his mother to Los Angeles where he took a Masters degree in Theatre at California State University.

Even when his acting career took off he continued to study, gaining a PhD in 1970 with his dissertation on show business blacklisting during the McCarthy era which he eventually published as a book": https://www.bbc.co.uk/news/entertainment-arts-15579361