This study examined the effects of objects, with and without social stimulus properties, on the behavior of children who are severely retarded, and compared such effects with behavior under conditions of minimal stimulation. It was found that these children approach, contact, grasp and interact significantly less often with objects which possess social stimulus properties than with objects which possess no social qualities. These results are discussed in relation to the ongoing debate on the importance of relationships in the reduction of challenging behavior. It is concluded that while having access to close-bonded relationships may be necessary for the reduction of challenging behavior, in some cases at least, it may not be sufficient.Many children show attachments to various stimuli early in life. Pacifiers are common up to 9 months of age and attachment to soft objects (e.g., blankets) begins at approximately 12 months. Such attachment increases rapidly up to 18 months and then remains stable until 36 months and subsides after 48 months (Passman & Halonen, 1979). Soft objects have been regarded as 'transitional phenomena' which function to symbolize the mother during the beginnings of abstract internal representations of external objects (Winnicott, 1953). A number of authors have suggested that soft objects may have an arousal or anxiety reduction function (c.f. Passman, 1987). Most children do not seem to form similar strong attachments to hard objects, thus suggesting that these stimuli have different functional properties.A minority of children, however, show unusual attachments to manipulable objects and rarely show attachments to soft objects (Berkson, 1983). Often these individuals have a diagnosis of mental retardation or autism and frequently