Most developmental theories propose reasons for behavior and changes in behavior due to influences from genetic and environmental factors. A behavioral change that occurs during development, from infancy to adulthood, is the increasing number of choices that are made. The purpose of this study was to investigate developmental theory as it relates to adolescent choice (influences, interactions, activity, preference, and acceptance) in the environment most readily controlled by adolescents, their bedrooms. Two hundred thirty-four eighth- and ninth-grade students responded to the Adolescent Development and Environments Research Survey. The survey assessed gender, grade, pubertal status, negative/positive passive and active genotype-environment effects, height and weight, and bedroom design and decoration influence, preference, activity, and acceptance (dislike-like). Results confirmed relations among gender and bedroom design preferences and activity. Girls' bedrooms contained a greater variety of items than did boys' bedrooms. Additionally, girls were overall more active in procuring items for their bedrooms than were boys. Grade differences (within gender) were identified for boys and girls for preferences, but not activity. Regarding pubertal status, Lo and Hi pubertal status girls differed in preferences, and the use of their own money to procure bedroom items. Lo and Hi pubertal status boys differed both in preferences and in bedroom location change. Perceived influences on adolescent bedroom design were associated with preferences for related items (e.g., the "Classes at school" influence category correlated positively with "Bookcase"). Regarding bedroom design acceptance, adolescents were less likely to like heir bedroom designs if they had ignored their parents' opinions about their bedroom design and instead furnished their bedrooms the way they wanted to. Girls who had no masculine items in their bedrooms were likely to have parents who gave the final word about bedroom design. Adolescents' friends influenced their frequency of bedroom design. With regard to obtaining bedroom items, girls and boys differed in the number and type of influences they reported. Previous studies of gender, age (grade), and pubertal status support these findings. Further, these findings support developmental theory suppositions as related to biosocial influences, negative/positive passive geneenvironment effects, and opportunity structures.