Infants (N = 59 boys and girls) were observed longitudinally at 13, 25, and 44 months of age in order to observe individual consistency and sex differences in the temperament variables of vigor, activity level, and persistence. In general, there were no sex differences and little individual stability over the first three years of life in the temperament variables studied. However, within age, vigor and activity were positively related.
All Science Journal Classification (ASJC) codes
- Developmental and Educational Psychology
- Clinical Psychology
- Life-span and Life-course Studies