When there is touch between cross-sex friends, no matter how much intimacy is involved in the friendship, men tend to be more aroused by the touch than women are. The researchers hypothesize that the research results may have been confounded by a social desirability bias because women may be less likely to admit arousal from the touch of a cross-sex friend out of fear of being negatively labeled by others. Afifi and Faulkner (2000) investigated instances in which individuals had sexual interactions with their platonic cross-sex friends. 51% of their sample had sex with their friend when they had no intention of pursuing a romantic relationship with them, and 34% of participants noted having sexual relations with their friend on multiple occasions. Within Afifi & Faulkner's study, of those who had sex with their friend, two-thirds stated that it improved their relationship and 56% stated that the relationship did not develop into something romantic. Sexual interactions are recognized as a possible outcome of cross-sex friendships (Monsour et al. 56). In the face of these sexual overtones, some welcome the sexual tension in their cross-sex friendship while others note that the potential intimacy could destroy their relationship (Monsour et al. 57). With the sexual component, some friends are hesitant to enter into romantic relationships due to the anticipated disapproval of their social network of peers (Akbulut and Weger 109). Cross-sex friends often have overlapping social circles (Akbulut and Weger 109). Each member in the cross-sex friendship depends on their social network for support and other emotional needs (Akbulut and Weger 109). Thus, potentially falling out of touch with members of one's own social network if the romantic relationship did not work out, is too costly for some cross-sex friends, even if they have engaged in sexual interactions (Akbulut and Weger 109). Nature/nurture The biological basis for cross-sex relationships cannot be found in ancient human history, because the way humans conducted their lives is different from the way current humans do now. Up until 10,000 years ago, or for over 99% of human history, humans’ ancestors lived their lives in a nomadic fashion, foraging in groups structured by reproductive partners and offspring — not unlike the way families are organized current-day. Females began reproducing at an early age, and males practiced behaviors that showcased ownership over their female partners in order to safeguard them from other males. There have only been scattered