George Bush explains the disappearance of knickers

Young George Bush explained the disappearance of knickers, in this scholarly study in 1960:

“On the disappearance of knickers: Hypotheses for the functional analysis of the psychology of clothing.” George Bush and Perry London, Journal of Social Psychology, vol. 51, no. 2, 1960, pp. 359-366. The paper begins:

“There are those of us for whom the rustling sound of corduroy has for many years been associated with memories of the almost indestructible kneelength trousers of our childhood. These memories, though not always pleasant…”

BONUS (possibly unrelated): A particular effect of the laundering of knickers