Yes it happens in groups, but exercise, excitement, or fear does it as well. I read last month a new interpretation of the DAVID. Almost perfectly correct but people have talked for years about how the penis is small. Some have said because he was young, but the article pointed out that he is actually poised with his sling to hurl the stone. That mean you had to consider he was looking at Goliath and with the adrenalin flowing scared, he shrunk. So Michaelangelo would agree with you it happens.
Happens to me sometimes when I do public and am nervous.
