Nancy Bayley

BAYLEY, NANCY (1899–1994)
Nancy Bayley, an eminent developmental psycholo-
gist, made significant contributions to the measure-
ment of infant intelligence and human development.
Born in Dalles, Oregon, on September 28, 1899, she
is best known for her work leading to the publication
of the Bayley Scales of Infant Development in 1968
and the revised edition in 1993. Her career, spanning
six decades, may have been influenced by her work on
48 BAYLEY, NANCYthe world-renowned Berkeley Growth Study, a longi-
tudinal study she initiated in 1928 that followed sub-
jects from infancy through adulthood. Her
productive career produced more than 200 publica-
tions about child development and she received many
awards. Bayley was the first woman to receive the Dis-
tinguished Scientific Contribution Award of the
American Psychological Association in 1966. Other
awards included the Gold Medal Award of the Ameri-
can Psychological Association in 1982 and the G.
Stanley Hall Award for distinguished contributions to
developmental psychology in 1971.
Prior to taking an introductory psychology course
with Edwin R. Guthrie, Bayley planned to teach En-
glish. With her interest in psychology sparked, Bayley
earned her master’s degree from the University of
Washington just two years after earning her bache-
lor’s degree at the same institution. She earned her
Ph.D. at the University of Iowa in 1926.
Bayley was descended from pioneering ancestors
including paternal grandparents who sailed around
Cape Horn to Victoria, British Columbia, and mater-
nal grandparents who traveled west by covered
wagon. Like her ancestors, Bayley has been described
as a pioneer who extended the study of human devel-
opment to a lifespan perspective and meticulously
studied a wide range of interests. She demonstrated
her adventuresome spirit when she carried out a se-
ries of studies measuring fear reactions on a galva-
nometer. According to a 1930 news account, she shot
off a .38 revolver in class to elicit and measure fear re-
sponse. Most of her studies were concerned with de-
tailed exploration of physical and mental growth and
intelligence predictability. She explored relation-
ships among measured characteristics and carefully
considered environmental and other influences on
her subjects. Bayley’s interests included the study of
physical maturation, body build, androgyny, and sex
differences. By 1962, through her studies of skeletal
maturation, she developed a means of predicting
adult height within one inch. The tables she devel-
oped are still used by endocrinologists.
Bayley’s career focused on developing tests for in-
fants and young children that correlate with other
measures and/or predict later intelligence. While
looking for data trends and groupings, she highlight-
ed individual differences in human development. She
did not believe intelligence was fixed and studied the
cause of variability in scores across the lifespan. She
was ahead of her time when she examined changes in
intelligence in adulthood in the 1950s. She was one
of the first to consider the impact of child-rearing atti-
tudes and behaviors on child development, and rec-
ognized that there are so many factors influencing
development that it would be difficult to isolate any
one factor, genetic or environmental, as possessing
the greatest importance.
Bayley was an outstanding developmental psy-
chologist distinguished by her contributions and her
early anticipation of current topics. Although she
spent most of her professional life at the University
of California, Berkeley, she also spent ten years at the
National Institute of Mental Health in Maryland be-
ginning in 1954 as chief of the Section on Early Devel-
opment, Laboratory of Psychology. Bayley was a
leader in her field who left a legacy of work and con-
tributions worthy of further study.
See also: INFANCY; INTELLIGENCE; MILESTONES OF
DEVELOPMENT
Bibliography
Lipsitt, Lewis P., and Dorothy H. Eichorn. ‘‘Nancy Bayley.’’ In
Agnes N. O’Connell and Nancy Felipe Russo, eds., Women in
Psychology: A Bio-Bibliographic Sourcebook. New York: Green-
wood Press, 1990.
Rosenblith, Judy F. ‘‘A Singular Career: Nancy Bayley.’’ Develop-
mental Psychology 28 (1992):747–758.
BAYLEY, NANCY  49Publications by Bayley
‘‘Mental Growth during the First Three Years: A Developmental
Study of Sixty-One Children by Repeated Tests.’’ Genetic Psy-
chology Monographs 38 (1933):1–38.
Studies in the Development of Young Children. Berkeley: University of
California Press, 1940.
‘‘On the Growth of Intelligence.’’  American Psychologist 10
(1955):805–818.
‘‘Implicit and Explicit Values in Science as Related to Human
Growth and Development.’’  Merrill-Palmer Quarterly 2
(1956):121–126.
‘‘Value and Limitations of Infant Testing.’’ Children 5 (1958):129–
133.
‘‘The Accurate Prediction of Growth and Adult Height.’’ Modern
Problems in Paediatrics 7 (1962):234–255.
‘‘Research in Child Development: A Longitudinal Perspective.’’
Merrill-Palmer Quarterly 11 (1965):183–208.
‘‘Behavioral Correlates of Mental Growth: Birth to Thirty-Six
Years.’’ American Psychologist 23 (1968):1–17.
Tracy L. Smith