Eyewitness researchers recommend that "not present" and "don't know" response options should be presented with police lineups. Although it is important that witnesses--most of whom are unlikely to be familiar with the identification task--are fully cognizant of all response options available to them, an understanding of how…

Eight experiments using as Ss either retarded children, normal children, or normal adults studied the relations of retardation and normal development to the perceptual process of identification. Two experiments were reported on the identification of stimuli varying in either one, two, or three dimensions. Retardates did not perform as well as…