There have been hints from the literature that painful experiences in early infancy might have long-lasting adverse psychological effects, which is why we are now so careful about using adequate analgesia for procedures. The most common of these worldwide is male circumcision. Researchers from Denmark looked for evidence of an association between circumcision and autistic spectrum disorder (ASD) (Frisch M et al. J R Soc Med 2015. doi:10.1177/0141076814565942). Using their national registers, they were able to study a cohort of over 340 000 boys born between 1994 and 2003 followed to age 9 years, of whom …