Abstract
In this paper, we summarize the design and measures in Project Talent, describe the Twin and Sibling sample, and present results for cognitive abilities. In most twin and family designs, the ‘shared environment’ includes factors specific to a family as well as between-family differences in macro-level variables such as socioeconomic status, community and geographical region. The school-based sampling design used in Project Talent provides a unique opportunity to partition the shared environment into variation shared by siblings, specific to twins, and associated with school- and community-level factors. We present results from our twin-sib-classmate model applied to cognitive abilities, including memory, abstract reasoning, spatial visualization, math and verbal abilities, and show how these abilities differ in the importance and sources of shared environment. These results address longstanding questions of the role of genetic, early life experiences, individual difference factors, and life course conditions in shaping later-life cognitive and physical well-being.