Maybe it is time to test the theory properly.

A control group of fully clothed folkies (men only), a group of semi clothed folkies (shorts, kilts), and a group of just naked folkies (woad & tatoo's optional). Trousers and shorts to be checked for tension by unbiased adjudicators, for those wearing kilts a wee sing on the sporran must tell the judges if they are au natural or covered.

Each group has to sing the same repetoir and alchohol strictly controlled to the same levels for each group. Ditto instruments for each group, though I suggest a lap played accordion or concertina not be used by the naked performers.

Judging strictly to be done on aural quality and not on clothes, tatoo's, quality of woad, or general physical appearance!

Trouble is you need a bunch of unbiased listeners so no family members (pun not intended)to watch there own kith and kin perform.

Potential PhD material in this?