Harry Harlow

Lore & Background

Harry Harlow was born on October 31, 1905, to Mabel Rock and Alonzo Harlow Israel in Fairfield, Iowa, the third of four brothers. In an unfinished autobiography, he recollected that his mother was cold to him and he experienced bouts of depression throughout his life. After a year at Reed College, he obtained admission to Stanford University through a special aptitude test, and after a semester as an English major with nearly disastrous grades, he declared himself a psychology major. He studied under Calvin Perry Stone, Walter Richard Miles, and Lewis Terman, receiving a PhD in 1930. At Terman's prompting, he changed his name from Israel to Harlow for fear of negative consequences of a seemingly Jewish last name, though his family was not Jewish.

Directly after completing his doctoral dissertation, Harlow accepted a professorship at the University of Wisconsin–Madison. Unable to persuade the Department of Psychology to provide adequate laboratory space, he acquired a vacant building down the street and, with graduate students, renovated it into the Primate Laboratory, one of the first of its kind. Under his direction, some 40 students earned their PhDs there. He married his first wife, Clara Mears, in 1932; they had two children and divorced in 1946. That same year he married child psychologist Margaret Kuenne, with whom he had two children. Margaret died in 1971 after a prolonged struggle with cancer, leading Harlow to depression treated with electro-convulsive therapy. In March 1972, he remarried Clara Mears, and they lived in Tucson, Arizona, until his death in 1981. He was buried alongside Margaret Kuenne at Forest Hill Cemetery in Madison, Wisconsin.

Harlow's early career involved nonhuman primate research at Henry Vilas Zoo, where he developed the Wisconsin General Test Apparatus (WGTA) to study learning, cognition, and memory. He discovered that monkeys developed strategies for his tests, which he described as 'learning to learn' or 'learning sets.' To study these sets, he established a breeding colony of rhesus macaques in 1932 and reared infants in a nursery setting, a controversial technique called maternal deprivation. Noticing that nursery-reared infants were reclusive, had social deficits, and clung to cloth diapers, Harlow investigated the mother–infant bond using surrogate mothers. His experiments created inanimate wire and wood surrogate mothers; infants became attached to their particular mother, recognizing its unique face. Harlow tested whether infants preferred bare-wire or cloth-covered mothers, with or without food. The monkeys overwhelmingly chose the cloth mother, only visiting the wire mother with food when needing sustenance.

Reader's Guide

Harlow's experiments on rhesus monkeys demonstrated the importance of caregiving and companionship to social and cognitive development, challenging behaviorist views that physical contact with infants was harmful. His surrogate mother studies showed that infant monkeys preferred cloth-covered mothers over wire mothers even when the wire mother provided food, indicating that comfort and contact were more crucial than feeding for attachment. Later, he cultivated infant monkeys in isolation chambers for up to 12 months, from which they emerged intensely disturbed. These experiments were ethically controversial and are cited by some researchers as a factor in the rise of the animal liberation movement in the United States. Harlow's work influenced debates on maternal care, child development, and institutionalization, building on John Bowlby's World Health Organization-sponsored report 'Maternal Care and Mental Health' and James Robertson's documentary 'A Two-Year-Old Goes to Hospital.' His findings supported Bowlby's emphasis on the primary caregiver's role beyond feeding. Harlow received numerous honors, including election to the National Academy of Sciences, the National Medal of Science, and presidency of the American Psychological Association. His legacy remains significant in psychology, though his methods are widely criticized on ethical grounds.

Did You Know?

• Harlow changed his surname from Israel to Harlow at Lewis Terman's prompting, due to fear of negative consequences of a seemingly Jewish last name, though his family was not Jewish.
• He developed the Wisconsin General Test Apparatus (WGTA) to study learning, cognition, and memory in primates at Henry Vilas Zoo.
• Harlow's surrogate mother experiments showed that infant monkeys overwhelmingly chose cloth-covered mothers over wire mothers, even when the wire mother held a bottle with food.
• Some researchers cite Harlow's experiments as a factor in the rise of the animal liberation movement in the United States.