My understanding so far : Jews circumcise their sons at the age of 8 days in order to mark an alliance between the newborn and God, and this tradition has carried on for thousands of years. It is also a central and very important tradition, equivalent to baptism in Christianity. Even casual Jews circumcise their sons, and circumcision is a strong requirement for converting to Judaism.
Reproducing is also culturally considered very important for Jews; single people are strongly encouraged to find a partner and couples are strongly encouraged to have as many children as possible.
Since both reproducing and circumcising are very important, I ask myself: What is the perceived effect of circumcision when it comes to sexuality? (It does not matter whether it is proven true - just what the Jews themselves think about it.) Is circumcision related to the Jewish views about family and sexuality?