Date of Award


Document Type

Open Access

Degree Name

Bachelor of Arts



First Advisor

David Cotter




emerging adulthood, siblings, closeness, family


This thesis explores closeness amongst sibling during their emerging adulthood focusing on the variations of sibling composition. Emerging adulthood (from the late teens to late 20s) is seen as an increasingly important stage of the lifecourse, but relatively little is known about the nature of sibling relationships at this age. A total of 54 young adults, 24 Union College students and their 30 siblings, completed surveys about their relationship with each other. In order to gain a full understanding of closeness siblings were asked questions focusing on similarities, intimacy, quarreling, affection, antagonism, admiration, emotional support, competition, instrumental support, dominance, acceptance, and knowledge. The data were analyzed by aggregating responses at the level of sibship group, and then compared according to the sex-composition of those groups (all sisters, all brothers, and mixed-sex groups). The survey results indicate that same-sex siblings reported the greatest amount of closeness. These results support the sex-commonality principle that claims same-sex siblings are closer than cross-sex siblings.