by the statement in your article that "circumcision reduces sensation ". How could anyone possibly know?
This is not such a difficult exercise or experiment to do. Not if you think about it. But it will only work with uncircumcised males.
With willing participants, it is not very difficult to find some manner of device (usually an elastic ring of some sort works fine enough) that can be placed just under the corona that will keep the foreskin permanently retracted from covering the glans.
Then, all that needs to be done, is have the discipline to remain this way for several weeks and record or report the degrees of change of sensation. At first the sensitivity will be overwhelming, especially when getting dressed and underclothing chaffs at the exposed glans. That in and of itself alone should indicate that uncircumcised organs are much more sensitive. But over time, several days or a week, chaffing will become less and less uncomfortable as sensitivity of the glans is reduced by constant friction. After a longer period of time, say a month or so, sensitivity will be even further reduced and virtually no feeling will be noted by contact with clothing. It will feel just about the same as with a covered glans.
Then there is sexual sensitivity. Participants will have to report on how stimulation may change. Invariably a different technique of masturbation will be applied. Simply rubbing the glans will no longer be sufficient, as is often the case with uncircumcised males. Many uncircumcised can even orgasm by rubbing the glans with the foreskin still covering the glans. It is also possible that the frenulum will become more the focus of stimulation.
In any case, this is such an easy experiment to conduct. I've done it myself for long periods, up to several months. This because of curiosity on the one hand and to sort of experience what all the fuss is about and also to actually feel firsthand the difference. And a difference there is, but you'll have to trust my word for it.
I invite anyone to give it a try. It is so simple to conduct but I guarantee that the first hours and days will be extremely uncomfortable. You may have to stop after several hours, give it a rest and then start again for a longer and longer period ... and I predict that your masturbation techniques will begin to change since simple stimulation of the glans will be insufficient.