Research is reviewed in support of the author's hypothesis that the majority (60 to 80 percent) of learning disabled children are not brain damaged but have above average spatial ability and major deficits in auditory-vocal memory processing which are genetic in nature. Research is reported to support other aspects of his hypothesis such as the lack of visual problems in the spatially competent learning disabled (SCLD) group, the frequent occurrence of a general maturational lag in SCLD males, and the common presence of hyperactivity is also due to an inherited maturational lag. Research is reviewed in the areas of birth order, sex of siblings, neurological impairment, pregnancy and perinatal factors, hyperactivity and brain damage, the nature of hyperactivity, the management of hyperactivity, the inheritance of specific abilities and disabilities, specific abilities underlying reading and other language processes, the good spatial ability but poor auditory-vocal memory skills in SCLD children, the incidence of SCLD children, and the effectiveness of remediation programs. (DB)