We found a matchYour institution may have access to this item. Find your institution then sign in to continue.TitleDifferentiation at higher levels of cognitive ability: evidence from the United States.AuthorsKane HD; Oakland TD; Brand CRPublicationThe Journal of genetic psychology, 2006, Vol 167, Issue 3, p327ISSN0022-1325Publication typearticleDOI10.3200/GNTP.167.3.327-341