Unless the "research" involved making identical guitars using the same materials, construction methods, scale length and electronics, i can't see how anyone could point to a feature such as the width of the guitar's 'waist' as any kind of scientific conclusion.
Doing proper scientific research is all about controlling variables. Even in analyzing only the body shape, you'd pretty much have to make the guitars out of carefully controlled synthetic materials, as we all know that the tonal quality of woods can vary from board to board, even if they came from the same tree.
The main factors separating the acoustic tones of Les Pauls from Strats and Teles are not only woods and the neck attachment methods, but also the scale length.