Many sexual fantasies are shared between men and women, possibly because of cultural influence.[1] However, there are still gender differences that have been found. Men are more likely than women to imagine being in a dominant or active role, whereas women are more likely to imagine themselves as passive participants.[2] Women's fantasies have significantly more affection and commitment,[3] whereas men are more likely to fantasise using visual imagery and explicit detail.[4][5] One explanation of this difference comes from the evolutionary perspective. Women have a higher minimum parental investment than males (they have 9 months of gestation prior birth and are then the main care givers, whereas men only have to provide sperm to ensure their genes are passed on) and are therefore more likely to want commitment from their partner in order to gain resources to improve their offspring's chance of survival.[6]