The first love
of the human infant is for his mother. The tender intimacy of this
attachment is such that it is sometimes regarded as a sacred or
mystical force, an instinct incapable of analysis. No doubt such
compunctions, along with the obvious obstacles in the way of objective
study, have hampered experimental observation of the bonds between
child and mother.
Though the data are thin, the theoretical literature on the subject
is rich. Psychologists, sociologists and anthropologists commonly
hold that the infant’s love is learned through the association
of the mother’s face, body and other physical characteristics
with the alleviation of internal biological tensions, particularly
hunger and thirst. Traditional psychoanalysts have tended to emphasize
the role of attaching and sucking at the breast as the basis for
affectional development. . . .
Now it is difficult, if not impossible, to use human infants as
subjects for the studies necessary to break through the present
speculative impasse. . . . Clearly research into
the infant-mother relationship has need of a more suitable laboratory
animal. We believe we have found it in the infant monkey. For the
past several years our group at the Primate Laboratory of the University
of Wisconsin has been employing baby rhesus monkeys in a study that
we believe has begun to yield significant insights into the origin
of the infant’s love for his mother. . . .
We have sought to compare the importance of nursing and all associated
activities with that of simple bodily contact in engendering the
infant monkey’s attachment to its mother. For this purpose
we contrived two surrogate mother monkeys. One is a bare welded-wire
cylindrical form surmounted by a wooden head with a crude face.
In the other the welded wire is cushioned by a sheathing of terry
cloth. We placed eight newborn monkeys in individual cages, each
with equal access to a cloth and a wire mother. Four of the infants
received their milk from one mother and four from the other. . . .
The monkeys in the two groups drank the same amount of milk and
gained weight at the same rate. But the two mothers proved to be
by no means psychologically equivalent. . . . Records
made automatically showed that both groups of infants spent far
more time climbing and clinging on their cloth-covered mothers than
they did on their wire mothers. . . .
These results attest to the importance—possibly the overwhelming
importance—of bodily contact and the immediate comfort it
supplies in forming the infant’s attachment for its mother. . . .
The time that the infant monkeys spent cuddling on their surrogate
mothers was a strong but perhaps not conclusive index of emotional
attachment. Would they also seek the inanimate mother for comfort
and security when they were subjected to emotional stress? With
this question in mind we exposed our monkey infants to the stress
of fear by presenting them with strange objects, for example, a
mechanical teddy bear which moved forward, beating a drum. Whether
the infants had nursed from the wire or the cloth mother, they overwhelmingly
sought succor from the cloth one; this differential in behavior
was enhanced with the passage of time and the accrual of experience. . . .
Thus all the objective tests we have been able to devise agree
in showing that the infant monkey’s relationship to its surrogate
mother is a full one. Comparison with the behavior of infant monkeys
raised by their real mothers confirms this view. Like our experimental
monkeys, these infants spend many hours a day clinging to their
mothers, and run to them for comfort or reassurance when they are
frightened. The deep and abiding bond between mother and child appears
to be essentially the same, whether the mother is real or a cloth
surrogate. . . .
The depth and persistence of attachment to the mother depend not
only on the kind of stimuli that the young animal receives but also
on when it receives them. . . . Clinical experience
with human beings indicates that people who have been deprived of
affection in infancy may have difficulty forming affectional ties
in later life. From preliminary experiments with our monkeys we
have also found that their affectional responses develop, or fail
to develop, according to a similar pattern.
Early in our investigation we had segregated four infant monkeys
as a general control group, denying them physical contact either
with a mother surrogate or with other monkeys. After about eight
months we placed them in cages with access to both cloth and wire
mothers. . . .
In the open-field test these “orphan” monkeys derived
far less assurance from the cloth mothers than did the other infants.
The deprivation of physical contact during their first eight months
had plainly affected the capacity of these infants to develop the
full and normal pattern of affection. . . . The long
period of maternal deprivation had evidently left them incapable
of forming a lasting affectional tie. . . .
The effects of maternal separation and deprivation in the human
infant have scarcely been investigated, in spite of their implications
concerning child-rearing practices. . . .
Above and beyond demonstration of the surprising importance of
contact comfort as a prime requisite in the formation of an infant’s
love for its mother—and the discovery of the unimportant or
nonexistent role of the breast and act of nursing—our investigations
have established a secure experimental approach to this realm of
dramatic and subtle emotional relationships. The further exploration
of the broad field of research that now opens up depends merely
upon the availability of infant monkeys. We expect to extend our
researches by undertaking the study of the mother’s (and even
the father’s!) love for the infant, using real monkey infants
or infant surrogates. Finally, with such techniques established,
there appears to be no reason why we cannot at some future time
investigate the fundamental neurophysiological and biochemical variables
underlying affection and love.