According to an opinion poll, 13 per cent of women in the United States cannot say whether they wear their tights under their knickers or over them. That's something like 12 million women walking around in a state of chronic foundation garment uncertainty. Perhaps because I so seldom wear ladies' clothing I don't fully appreciate the challenge involved, but I am almost certain that if I did wear tights with knickers I would know which was on top. More to the point, if a stranger with a clipboard came up to me in the street and asked me how my underwear was configured, I don't believe I would tell him that I didn't know.
Bill Bryson