“…First, genes are important to familial resemblance in reading ability and disability (e.g., Harlaar, Spinath, Dale, & Plomin, in press;Pennington & Smith, 1983; in press a; Stevenson, Graham, Fredman, & McLoughlin, 1987). Second, genetic influences are important for components of reading ability such as phonological awareness/decoding, reading comprehension, spelling, orthographic knowledge, and rapid automatized naming (see Olson, Forsberg, & Wise, 1994;Olson, Gillis, Rack, DeFries, & Fulker, 1991;Knopik, Alarcon, & DeFries, 1998;Gayan & Olson, 2003;Compton, Davis, DeFries, Gayan, & Olson, 2001).…”