Question: When did Margaret Kuenne Harlow's husband die?
Sentence (from "Harry Harlow"): Harry Frederick Harlow (October 31, 1905 – December 6, 1981) was an American psychologist best known for his maternal-separation, dependency needs, and social isolation experiments on rhesus monkeys, which manifested the importance of caregiving and companionship to social and cognitive development.
Relevant evidence: Yes