HARLOW, HARRY (1905–1981)
Harry Harlow received his B.A. and Ph.D. in psychol-
ogy from Stanford University and then joined the fac-
ulty at the University of Wisconsin, where he
established the Psychology Primate Laboratory.
When Harlow’s lab joined the Wisconsin Regional
Primate Laboratory in 1964, Harlow became the di-
rector of the merged research center. He is most fa-
mous for his scientific study of love. Starting in 1957,
Harlow systematically manipulated the rearing condi-
tions of baby rhesus monkeys. Some were reared with
mothers, others without. Harlow provided ‘‘surrogate
mothers’’ either of terry cloth wrapped around a
sloped wooden block or of wire mesh. Nippled bottles
that fed milk on schedule were attached to the upper
thoracic section of the surrogates.
Harlow’s findings disproved predictions by rein-
forcement theorists that love is a secondary or derived
drive associated with the reduction of hunger/thirst.
Whether they received milk exclusively from a wire
mother or a cloth mother, babies clung to the cloth
mother up to eighteen hours a day. Nursing seemed
primarily to ensure frequent and intimate body con-
tact of infant with mother. At 250 days, monkeys
reared alone initially showed fear and disturbance
when presented with a cloth mother, but gradually
learned to play on her and use her for comfort when
frightened. Harlow’s primate findings provided early
confirmation of later attachment research. When
frightened or upset, securely attached human infants
demand and obtain comfort from proximity to their
mothers. The cloth mother served as a comfort in
open field tests. Scary toys such as a wind-up, drum-
ming teddy bear frightened the infant monkeys. They
screamed and cowered while crouching immobilized.
But when the cloth surrogate mother was present, the
baby would climb on and clutch her, then relax
enough to explore the room and toys adventurously.
Total emotionality scores were cut in half when the
cloth mother was present, but not when a cloth diaper
was present.
Harlow demonstrated the staying power of infant
monkey ‘‘love’’ by removing some infants from their
cloth surrogates for five months. Reunion episodes
revealed that deprivation had intensified the tie to
the ‘‘mother.’’ Reunited monkeys clung to the cloth
mother and would not descend for exploration dur-
ing three-minute test sessions.
Baby monkeys without playmates or real mothers
behaved in socially incompetent ways. Six months of
social isolation rendered the animals permanently in-
adequate socially. Infant-infant play was slower for
cloth-mother-reared infants, who caught up in about
a year. Sexual behaviors were abnormal for the surro-
Harry Harlow’s primate studies offered important insights into
issues such as human maltreatment of infants and familial love.
(Harlow Primate Laboratory, University of Wisconsin)gate reared monkeys. If impregnated, mothers be-
haved quite abnormally. Infants of motherless
mothers showed extremes of sexuality and aggres-
siveness. This primate research contributed clinical
insights to issues of human maltreatment of infants.
Harlow’s work won him election to the National
Academy of Sciences. He received the National Medal
of Science in 1967 and the Gold Medal Award of the
American Psychological Association in 1973.See also: ATTACHMENTBibliography
Publications by Harlow
‘‘The Nature of Love.’’ American Psychologist 13 (1958):673–85.
‘‘The Development of Affectional Patterns in Infant Monkeys.’’ In
B. M. Foss ed., Determinants of Infant Behaviour. London:
Methuen, 1959.
Harlow, Harry F., and M. K. Harlow. ‘‘Social Deprivation in Mon-
keys.’’ In M. L. Haimowitz and N. R. Haimowitz eds., Human
Development. New York: Thomas Y. Crowell, 1966.
Alice Sterling HonigHEAD START
Head Start was launched in 1965 as part of the Lyn-
don Johnson administration’s ‘‘war on poverty,’’ with
the goal of bridging the school-readiness gap that ex-
ists between disadvantaged and more privileged pre-
school children. The program calls for extensive
involvement of parents, and it attempts to provide the
children with better preschool skills. Since its incep-
tion, Head Start has been extensively researched, and
studies have shown mixed results. The immediateHEAD START 173