Forty-four children who had been born preterm and their mothers participated in the follow-up study. At 3 and 14 months (corrected age) cognitive development was assessed using the BOS 2–30, the Dutch version of the Bayley Scales of Infant Development. The BOS yields measures of mental and motor development. At 7.5 years, intelligence was measured using the WISC-RN, the Dutch version of the WISC-R. A composite measure of maternal rigidity, tapping rigidity as a personality trait and rigid attitudes to child-rearing was used. The results of a multiple regression analysis indicated that maternal rigidity, measured in the first year of the child's life, was not associated with mental performance at 3 or 14 months. At 7.5. years, however, it was strongly associated with cognitive development, contributing uniquely to performance IQ. [ABSTRACT FROM AUTHOR]