A practice of removing the foreskin from the human male penis to expose the glans.
Only common in the Jewish faith and in the United States, the vast majority of the developed world having paid attention to the research indicating it's a completely unnecessary and barbaric practice. Neonatal circumcision is illegal in a few countries and never offered on nationalised health care unless there is a problem with the ability of the foreskin to retract and expose the glans.
Reduces sensitivity by causing callousing of the glans tissue and if performed incorrectly can result in almost complete loss of penile sensation and resulting sexual dysfunction.
The vast majority of human males are not circumcised.
Boyle et al. stated that "the genitally intact male has thousands of fine touch receptors and other highly erogenous nerve endings—many of which are lost to circumcision, with an inevitable reduction in sexual sensation experienced by circumcised males." They concluded, "Evidence has also started to accumulate that male circumcision may result in lifelong physical, sexual, and sometimes psychological harm as well."
Sorrells et al., using monofilament touch-test mapping, found that the foreskin contains the most sensitive parts of the penis, noting that these parts are lost to circumcision. They also found that "the glans of the circumcised penis is less sensitive to fine-touch than the glans of the uncircumcised penis."