David Baxter was a fictional character on the series, The Mary Tyler Moore Show. He was played by child actor, Robbie Rist. The Mary Tyler Moore Show is an American television sitcom that aired on CBS from September 19, 1970 to March 19, 1977. ... Robbie Rist as Cousin Oliver on The Brady Bunch Robbie Rist (born April 4, 1964) is an American actor. ...
Genius child.
David was the adopted son of Ted Baxter and Georgette Franklin Baxter. They adopted him when they mistakenly thought they couldn't have children of their own. (Which was disproved when Georgette gave birth to their daughter, Mary Lou). At first, David was thought to be slow in school, but was later discovered to be a genius. He was also spoiled, at first, but that was later receded, as he became more a part of his family. He was also a great brother to his baby sister. Ted Baxter was a fictional character on the long running situation comedy, The Mary Tyler Moore Show. ... Georgette Franklin Baxter was a fictional character on The Mary Tyler Moore Show. ...
At first, he resented his family, but later grew to love them. Presumably, David remained in Minneapolis, having become a good man working at a university or somewhere along those lines.