Age of partners at first intercourse among Danish males and females

In 1984-1985 a representative sample of 286 Danish women (response rate = 75.3%) and 336 Danish men (response rate = 77.8%), ages 16-20 years, was interviewed about their first sexual intercourse. A cumulative frequency function was constructed and the median age at sexual debut was estimated at 16.8 years for both male and female. Generally the age difference between the partners at first intercourse was only a few years. However, the young women almost never reported their first sexual partner as younger than themselves. A cross-check was made of the information given by two homogeneous subsamples of the 47 young women and 80 young men who had their first sexual intercourse with a partner who was also a debutant. Self-reported age among the males differed significantly from the age of the first sexual partner as stated by the females in these subsamples. Therefore, there is bias in the reporting of age of partner at first intercourse. As the self-reported age at first sexual intercourse by young women agrees with the age of first partner as stated by young men, the bias seems to manifest itself predominantly as a systematic misreporting in the age of male partners of debutant females.