LAUSR

Abstract. In the 1980s, psychologists extended attachment theory into the domain of adult romantic bonds by proposing that romantic love can be conceptualized as a process of becoming attached ( Hazan & Shaver, 1987 ). From this perspective, individuals differ in two primary attachment dimensions: anxiety, the extent to which they worry about abandonment in their romantic relationships, and avoidance, the extent to which they are uncomfortable with interdependence and closeness. Research suggests that people perceive the rearing environment as a primary cause of people’s romantic attachment styles ( Tillman et al., 2008 ). If it is, family members should be similar in attachment-related anxiety and avoidance. To test this idea, we collected romantic attachment data on 965 US college students and the family members they nominated (205 siblings, 245 mothers, and 182 fathers). The students and family members in our sample showed negligible-to-weak resemblance in attachment-related anxiety and avoidance. Because previous studies have shown substantial similarity between identical twins and weak similarity between fraternal twins in romantic attachment styles, our data reinforce the possibility that nonshared environmental influences (such as individuals’ specific relationship histories) and genetic influences are the primary sources of individual differences in attachment-related anxiety and avoidance.