As with any claim of psychology those concerning the mental effects of circumcision are difficult to be proven in a strict formal and objective scientific style. Circumcision cannot be undone and is not a subject of experimentation. Its effects may be multivalent, unobvious and develop slowly in time. Their judgment requires non-judgmental open-mindedness that is uncommon to specialized science and religion. For that reason we find statements about the psychological effects of circumcision instead of scientific proofs.
The bias of researchers is another unsurpassable difficulty. Please join us in getting a laugh while reading the following example of prejudice reflected in Wikipedia: “Moses et al. (1998) state that “scientific evidence is lacking” for psychological and emotional harm, citing a longitudinal study which did not find a difference “in relation to a number of developmental and behavioural indices.”[i] Is this a proxy or a replica of the Old Testament hero who delivers a modernized version of the circumcision covenant?
Can anyone take seriously the assertions about the insignificance of a body part made by people who lack it? Is it possible that researchers who have a deficiency are unbiased toward its function and possible effects? Can we expect that circumcised scholars can objectively examine the importance of foreskin? Can a blind man be an authority on sight? After all, even Freud who unravelled sexuality to threads failed to spot the effects of circumcision.