Abbey and Melby (1986) found that males perceived more sexual intent than females in both ambiguous and nonambiguous nonverbal situations.
Levesque et al (2006) also found that men attributed more sexual interest after brief interaction than women, but that women tended to generalize attraction to positive personality characteristics more than men. Levesque et al also found that masculine women tended to sexualize opposite-sex interactions more than feminine women, but there were no differences between "masculine" and "feminine" men (rated using the
BSRI).
Levesque et al did not provide the ages or recruitment methods of their participants, nor was I able to find this information about Abbey and Melby's experiments, although later studies by Abbey (e.g.
1987,
1995) use college student samples. Also, no studies seem to have been done to assess the level of sexual intent inferred by gay men and lesbians in same or opposite sex pairings.
In my experience, men assume no one is hitting on them, and women assume everyone is hitting on them. Obviously, this is an oversimplification. I've known and dated guys who were supremely arrogant and women who were painfully self-conscious. However, I still found that the arrogance in men tended to translate to thinking they would get a positive response to flirtation, and the self-deprecating women assumed that the flirtation was non-serious, or sexual only. It's a self-fulfilling observation in my case. I tend to assume that no one is flirting with me because they see me as male, and wonder if they're seeing me as something else if they make their intentions known.