Psychopharmaeologia (Berl.) 38, 105--110 (1974) 9 by Springer-Verlag 1974 Assessment of Effects of Ethanol Self-Administration on Social Interactions in Alcoholics Roland Griffiths, George Bigelow, and Ira Liebson Department of Psychiatry, Baltimore City Hospitals, and Johns I-Iopkins University School of Medicine, Baltimore, maryland, USA Received September 21, 1973; Final Version April 16, 1974 Abstract. Five volunteer chronic alcoholics participated in an experiment in which the availability or non-availability of a daily ration of 12 ounces (360 ml) of 95-proof ethanol (133.68 g ethanol) was randomly determined. For all subjects, rates of social interaction were significantly higher on ethanol days than non-ethanol days. The study demonstrates the feasibility of using complex molar units of human behavior as dependent variables in behavioral pharmacology research. Key words: Ethanol -- Social Interactions -- Human Subjects -- Alcoholics. Experimental clinical behavioral pharmacology typically relies for data upon the subjective ratings of observers or of drug recipients them- selves (Lehmann, 1968). Within basic research settings discrete and objectively measurable molecular units of human behavior have been shown to bear systematic relations to drug administration (Dews and Morse, 1958; Hollis and St. Omer, 1972). However, behavioral pharma- cology research has been slow to develop objectively quantifiable meas- ures for more molar units of clinically meaningful human behavior. This gap in technology is illustrated by the fact that there remains dis- agreement about the effects of such a ubiqnitious drug as ethanol on such a ubiquitious class of human activity as social behavior. The present study demonstrates quantitatively that a period of ethanol self-admin- istration results in a significant increase in the rate of social interactions by alcoholic participants. Clinicians have often characterized the alcoholic as a social isolate with little motivation, capacity or ability to sustain interpersonal rela- tionships (Mowrer and Mowrer, 1945; Zwerling and Rosenbaum, 1959). Using quantitative measures in a residential experimental ward situation Nathan and O'Brien (1971) demonstrated that alcoholics spent less time in the social ward area than non-alcoholics. These investigators argue that lone drinking represents adaptive behavior for the alcoholic. Unfortunately their experimental design did not permit an unambiguous interpretation of the direct effects of ethanol self-administration on