• Schizophrenic patients were tested on psychophysiologic measures within their homes and in the laboratory. Sweat gland activity and heart rate changes when patients encounter novel situations such as life events, together with the home atmosphere generated by a critical or overinvolved relative, confirmed objectively the importance of previous social measures of these factors in determining relapse. Drug effects were also found to be modified by these social factors. Environmental and socially induced changes found in the home were undetectable in the laboratory situation.