title: Hormone-behavior associations in early infancy.
abstract: The physiological significance of hormonal changes in early postnatal life is emerging, but the behavioral significance in humans is unknown. As a first test of the relationship between hormones and behavior in early infancy we measured digit ratios and salivary hormone levels in forty-one male and female infants (3-4 months of age) who watched a video depicting stimuli differentially preferred by older males and females (toys, groups). An eye-tracker measured visual fixations and looking times. In female infants, hormones were unrelated to visual preferences. In male infants, higher androgen levels predicted stronger preferences for male-typical stimuli. These data provide the first evidence for a role for hormones in emerging sex-linked behavior in early development.
authors.affiliation: Deparment of Psychology, TAMU-2435, Texas A&M University, College Station, TX 77845, USA. gma@psyc.tamu.edu
authors.forename: Gerianne M
authors.initials: GM
authors.lastname: Alexander
authors.forename: Teresa
authors.initials: T
authors.lastname: Wilcox
authors.forename: Mary Elizabeth
authors.initials: ME
authors.lastname: Farmer
mesh_terms: D002657:Child Development; D002755:Choice Behavior / Q000502:physiology*; D004192:Discrimination, Psychological / Q000502:physiology; D004958:Estradiol / Q000378:metabolism*; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D005385:Fingers / Q000033:anatomy & histology; D006801:Humans; D007223:Infant; D018730:Infant Behavior / Q000502:physiology*; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation; D010988:Play and Playthings; D012463:Saliva / Q000378:metabolism; D012737:Sex Factors; D013739:Testosterone / Q000378:metabolism*; D014796:Visual Perception / Q000502:physiology
chemical_list: D013739:Testosterone; D004958:Estradiol