Behavioral Dimensions in One-Year-Olds and Dimensional Stability in Infancy

Abstract

The purpose of the study was to establish dimensions of functioning that account for interindividual variation in behavior in the middle infancy period and to investigate the stability of the dimensional structure during a large part of the infancy period. Factor analyses were performed on parent questionnaire data for 357 infants, aged 11 to 15 months. An orthogonal 8-factor solution was preferred and cross-validated on subsamples. Comparisons with factor solutions previously obtained for 3 to 6 and 6 to 10 month-old infants revealed similarity for seven of the factors, both in terms of general dimensional content and item loading patterns. Thus, the dimensional structure of infants' behavioral repertoire was shown to be highly stable over the 3 to 15 months age period. The seven factors were named Intensity/Activity, Regularity, Approach-With drawal, Sensory Sensitivity, Attentiveness, Manageability, and Sensitivity to New Food. The additional eighth factor, appearing only in the oldest sample, was named Adaptability.