It's a very tricky thing to study. Maybe you could look at people who were circumcised then immediately adopted? Maybe twin studies? I think this connection is

It's a very tricky thing to study. Maybe you could look at people who were circumcised then immediately adopted? Maybe twin studies? I think this connection is so far-reaching that you could never truly resolve the confounding variables. Frankly, I don't really care about the results anyway! As you neatly put it, we already know that infant circumcision is barbaric. That's enough!