Doctor Kinsey had heard -- and there was a theory going around at the time, this being the 1940s -- that the force with which semen is thrown against the cervix was a factor in fertility.
Dokter Kinsey telah mendengar -- ada teori yang muncul saat itu, sekitar tahun 1940-an yaitu gaya dari air mani dilemparkan dari leher rahim berpengaruh terhadap kesuburan.