often changes. Sexual attraction in cross-sex friendships is often dealt with in one of three ways: management of this attraction through communication or an internal decision not to pursue the attraction in order to preserve the friendship, a sexual relationship forms then dissipates, or sex becomes a part of the friendship. When participants in the study by Halatsis and Christakis (2009) were asked about their experience with sexual attraction in cross-sex friendships, over 50% had experienced attraction, and over 50% of that group had expressed or acted on their sexual attraction. However, men had a tendency to be more attracted to their cross-sex friends, and a higher tendency to act on that attraction. Only 16% of individuals who had acted on their sexual attraction claimed that their friendship ended as a result, otherwise the friendship remained intact or transformed into a romantic relationship. Reeder (2000) found that there are four types of attraction within cross-sex friendships: subjective physical/sexual attraction, objective physical/sexual attraction, romantic attraction, and friendship attraction. Subjective physical/sexual attraction occurs when one of the individuals in the friendship is physically attracted to the other. Objective physical/sexual attraction happens when one individual thinks that the other is attractive in general, yet they are not attracted to the person. Romantic attraction within the cross-sex friendship occurs when one of the individuals within the friendship desires to turn the friendship into a romantic relationship because they believe he or she would make a good girlfriend or boyfriend. Friendship attraction is simply when an individual feels very platonically connected to his or her friend. The four types can coexist together within a friendship or can occur separately. Furthermore, the type of attraction that an individual feels within a cross-sex friendship can change over time. Within Reeder's (2000) sample, friendship attraction is the most prevalent type of attraction within cross-sex friendships. Even when participants felt other types of attraction within their cross-sex friendships, they prioritized their friendship attraction so that the relationship would not be ruined. Protection Historically, women are more vulnerable due to their smaller stature and lesser strength, on average, compared with men. Thus, women have consistently needed to secure protection for themselves. Seeking protection from men would have been an evolutionary advantage as women who do so increase their reproductive success, which has caused an evolved preference for men who are willing and able to offer protection. Therefore, it is not