The study subjects were 272 female and 268 male undergraduate psychology students, with a mean age of 19. For each of 11 scenarios describing dates in which who initiated, who paid, and the dating activity were manipulated, the subjects indicated how much they thought the woman wanted sex (sex-willingness ratings) and how justified the men would be in having sex with her against her wishes (rape-justifiability ratings). Participants met in groups of 50 and filled out questionnaires anonymously. Results showed that sex-willingness and rape-justifiability ratings were highest when the woman initiated the date, when they went to the man's apartment, and when the man paid the dating expenses. Men's sex-willingness ratings were consistently higher than women's, suggesting that a man may overestimate his date's interest in sex and may later feel 'led on,' which some males regard as justifying rape. Rape-justifiability ratings were higher for men than for women and higher for traditional persons -- especially traditional men -- than for nontraditional persons. Both theoretical issues and practical implications of these results are discussed. Tabular data and 32 references. (Author abstract modified)