stimulation and fantasies about casual sex encounters, regardless of sexual orientation. On the other hand, women's fantasies tend to be more focused upon mental sexual stimulation and contain more emotion and connection. Thus, women are more likely to report romantic sexual fantasies that are high in intimacy and affection, for instance associating their male partner with heroism and viewing them as chivalric rescuers. Evolutionary theory offers an explanation for this finding, such that women may be likely to show commitment to their male partner in return for his investment of resources to help raise her offspring, thus increasing offspring chance of survival. Types of sexual fantasies Much research has been conducted which has highlighted several gender differences in sexual fantasies. Some of the patterns which have frequently emerged include men's greater tendency to report sexual fantasies falling in the following categories: exploratory, intimate, impersonal, and sadomasochism. Exploratory fantasies include those of homosexual encounters and group sex, whilst fantasies of watching others engage in sexual intercourse and fetishism are classed as impersonal sexual fantasies. Women are also likely to report fantasies involving the same-sex partner, or those with a famous person, although both sexes have been found to prefer intimate fantasies over the other three types outlined, including fantasies of oral sex and sex outdoors. Frequent themes Another way the sexes differ is that men are much more likely to fantasize about having multiple sexual partners (i.e., having threesomes or orgies) compared to women and seek greater partner variation in their sexual fantasies. Evolutionary theory suggests that this may be due to men's capacity to produce many offspring at any one time by impregnating multiple females, and thus predicts that males will be more open to the concept of multiple partnerships in order to increase reproductive success and continue their genetic line. The sexes also differ in terms of how much they fantasize about dominance and submission. Men fantasize equally often about dominance and submission, whereas women fantasize about submission more frequently than dominance. Despite these differences, it is important to note that most individuals do not conform to these gendered sexual stereotypes, and that male sexuality is not innately aggressive, nor is female sexuality inherently passive, and that these stereotypes may decline with age. Sexual fantasies may instead vary as a result of individual differences, such as personality or learning experiences, and not gender per se. Indeed, it has been