The current thesis investigated the hypothesis that evolved psychological mechanisms producing adult attachment strategies are sensitive to personal and contextual inputs linked to costs and benefits of alternative attachment strategies. Three studies were designed to 1) identify the link between the inputs “early parental environment, speed of life, and mate value” and attachment strategies; 2) examine temporary activation of adult attachment mechanisms in response to a blind date opportunity with individuals varying in physical attractiveness; and 3) test the relationship between physical attractiveness and secure base use behavior in couples experimentally manipulating physical attractiveness. Study 1 results showed adult attachment mechanisms up-regulated both men’s and women’s attachment anxiety in response to low mate value and low quality early parental environment; men’s attachment avoidance in response to fast life speed and low quality early parental environment; women’s attachment avoidance in response to fast life speed and low mate value. Study 2 results showed both men and women exhibited an anxious attachment strategy in response to a blind date opportunity with an individual of high physical attractiveness whereas only women exhibited an avoidant strategy in response to a blind date opportunity with an individual of average physical attractiveness. Study 3 results revealed a positive correlation between women’s ratings of facial attractiveness and secure base use scores; between individuals’ physical attractiveness and their secure base scores specifically among individuals who compared themselves to attractive others. These results enhance the understanding of the origins of individual differences in adult romantic attachment.