Development and Psychopathology


Lexical decision as an endophenotype for reading comprehension: An exploration of an association

Adam Naplesa1, Len Katza2 and Elena L. Grigorenkoa1a3a4 c1

a1 Yale University

a2 University of Connecticut

a3 Moscow State University

a4 Columbia University


Based on numerous suggestions in the literature, we evaluated lexical decision (LD) as a putative endophenotype for reading comprehension by investigating heritability estimates and segregation analyses parameter estimates for both of these phenotypes. Specifically, in a segregation analysis of a large sample of families, we established that there is little to no overlap between genes contributing to LD and reading comprehension and that the genetic mechanism behind LD derived from this analysis appears to be more complex than that for reading comprehension. We conclude that in our sample, LD is not a good candidate as an endophenotype for reading comprehension, despite previous suggestions from the literature. Based on this conclusion, we discuss the role and benefit of the endophenotype approach in studies of complex human cognitive functions.


c1 Address correspondence and reprint requests to: Elena L. Grigorenko, Child Study Center, Yale University, 230 South Frontage Road, New Haven, CT 06519; E-mail: