Photo: flickr/Nils SautterFrom Brad Pitt to Elizabeth Taylor, many of the most beautiful celebrities also boast rocky private lives. But is this due to their attractiveness, their celebrity, or something else? This study investigated the relationship between physical attractiveness and relationship longevity, for both celebs and normal folks. They found that "those rated as more attractive in high school yearbooks were married for shorter durations and more likely to divorce," a result that also proved true for high-profile celebrities. The authors go on to associate this effect with the "derogation of attractive alternatives" - i.e., physically attractive people are more tempted by or vulnerable to "relationship threats" (other hot people) when they are dissatisfied with their current relationship. So there you have it: Brangelina may have been doomed from the start. It's just science.Attractiveness and relationship longevity: Beauty is not what it is cracked up to be "Across four studies, we examined the relational repercussions of physical attractiveness (PA). Study 1 (n = 238) found that those rated as more attractive in high school yearbooks were married for shorter durations and more likely to divorce. Study 2 (n = 130) replicated these effects using a different sample (high-profile celebrities). Study 3 (n = 134) examined the link between PA and the derogation of attractive alternatives, a relationship maintenance strategy. Study 4 (n = 156) experimentally manipulated perceived PA and examined its relation with both derogation of attractive alternatives and current relationship satisfaction. PA predicted likelihood of relationship dissolution and decreased derogation of attractive alternatives. Furthermore, PA predicted greater vulnerability to relationship threats—in this case, relationship alternatives—resulting from poor relationship satisfaction." Related content: Whose cheating is more likely to doom a marriage: husband or wife?Twitter: ruining marriages since 2006.How many notches on your bedpost make you most attractive? The answer might surprise you.