John T. Molloy, author of the 1975 best seller Dress for Success, turns his pop-science expertise to the field of matrimony. In his new book, Why Men Marry Some Women and Not Others (Warner), he advises would-be brides:
--If you wish to marry, you must insist on it. Commit yourself to the idea.
--If you're involved with a "stringer"--a man who strings women along--set a deadline. If you're not headed to the altar in six months, move on.
--A majority of male college graduates between 28 and 33 are in their "high commitment" years and are likely to propose.