Quantitative Genetics of Response to Novelty and Other Stimuli by Infant Rhesus Macaques (Macaca mulatta) Across Three Behavioral Assessments.
Primate behavior is influenced by both heritable factors and environmental experience during development. Previous studies of rhesus macaques (Macaca mulatta) examined the effects of genetic variation on expressed behavior and related neurobiological traits (heritability and/or genetic association) using a variety of study designs. Most of these prior studies examined genetic effects on the behavior of adults or adolescent rhesus macaques, not in young macaques early in development. To assess environmental and additive genetic variation in behavioral reactivity and response to novelty among infants, we investigated a range of behavioral traits in a large number (N= 428) of pedigreed infants born and housed in large outdoor corrals at the Oregon National Primate Research Center (ONPRC). We recorded the behavior of each subject during a series of brief tests, involving exposure of each infant to a novel environment, to a social threat without the mother present, and to a novel environment with its mother present but sedated. We found significant heritability (h2) for willingness to move away from the mother and explore a novel environment (h2= 0.25 ± 0.13;P= 0.003). The infants also exhibited a range of heritable behavioral reactions to separation stress or to threat when the mother was not present (h2= 0.23 ± 0.13-0.24 ± 0.15,P< 0.01). We observed no evidence of maternal environmental effects on these traits. Our results extend knowledge of genetic influences on temperament and reactivity in nonhuman primates by demonstrating that several measures of behavioral reactivity among infant rhesus macaques are heritable.
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030.
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GL
Fawcett
Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892.
A M
AM
Dettmer
Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida 32610.
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D
Kay
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030.
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M
Raveendran
Department of Psychology, Brigham Young University, Provo, Utah 84602.
J D
JD
Higley
Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania 15213.
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Ryan
Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania 15213; and Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon 97006.
J L
JL
Cameron
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030.
J
J
Rogers
Anxiety; Heritability; Maternal environmental effects; Temperament