Prof. Peter Boyd is engaged to brainy dean's daughter Valerie. But the Dean wants the engagement ended when he finds that Peter's father was a crook. To prove that environment is more important than heredity, Peter adopts lab chimp Bonzo and vows to "teach this monkey the difference between right and wrong." He hires young nursemaid Jane Linden to "mother" Bonzo; but will Valerie understand if she finds Jane about the house?