Mr Kahn has examined the probable quantitative result of such factors as these in certain hypothetical special cases. But, clearly, it is not possible to carry any generalisation very far.
First of all, I believe it is a mistake to base our views on broad generalisations about the characteristics of men and women as such stereotypes are often inaccurate.
" They're extremely rational and they're much better in some ways at doing inferential learning" – using patchy information to make accurate generalisations about a messy world – " than any other creature that we know of."
The Common Reader Volume 1 26 Essays on Jane Austen, George Eliot, Conrad, Montaigne and Others
A generalisation of this kind will, of course, even if it has some degree of truth when applied to the body of literature, be changed profoundly when a writer of genius sets to work on it.
There are broadly three possible answers: (1) that it is itself known a priori; (2) that it is a postulate; (3) that it is an empirical generalisation from past instances in which it has been found to hold.