STABILITY OF INHIBITION IN A SWEDISH LONGITUDINAL SAMPLE

2 of the major questions prompted by recent research on inhibition are: (1) Should inhibition be considered a trait dimension, or do those who manifest extreme inhibition constitute a discrete personality type? (2) Are there sex differences in stability of inhibition? We addressed these questions using mothers' ratings over 16 years and psychologists' ratings over 6 years of a Swedish longitudinal sample. From the mean of mothers' 18- and 24-month ratings and the mean of psychologists' 18- and 24-month ratings, we predicted later ratings through 16 years. We performed these analyses for children constituting the extreme 10%-15% from each end of the distribution and then for children not rated as extreme. Ratings were more stable for children in the extreme groups than for those in the nonextreme groups through 6 years; however, only for the inhibited girls did early inhibition predict inhibition into adolescence. We conclude that culturally shared notions of gender-appropriate behavior influence the stability of inhibition.