usage query

[Marilyn Frye]

I've come across the speculation that north american English speakers
use the words 'sex' and 'gender' interchangeably, and also the words
'male' and 'masculine',   and the words  'female' and 'feminine'.   My
linguistic intuition is that these terms may be used interchangeably in
some contexts, but that the patterns of usage overall are, in the case
of each pair, distinct.  My intuitions are not, however, coming forth
with the rules governing the usages.

Have there been any empirical studies of the non-specialist,
not-academic usage of these terms, in say the current and preceding
decade?

Thanks.

Marilyn