Attraction within these friendships can cause challenges. Sexual attraction can arise for a variety of reasons in cross-sex friendships. In a study by Halatsis and Christakis (2009), participants cited social pressures and emotional vulnerability as reasons for sexual attraction arising in a cross-sex friendship. A social pressure that may prompt sexual attraction between cross-sex friends is the perceptions other friends have of their relationship and emotional vulnerability coupled with closeness may provoke sexual attraction between cross-sex friends. When sexual attraction develops in a friendship, it can corrupt the friendship and individuals state that behavior 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.