Two inbred strains of mice were opposed in measures of tube-dominanc e, food-dominanc e, and aggression, using matched pairs of individual opponents. There were stable strain differences on all three measures, and Ss within strains were highly similar to each other in performance. Results on the food-dominance and aggression measures were concordant, while performance on the tube-dominance test was negatively related to the other two measures.While uncontrolled observation of social dominance in infrahuman animals has long been reported, there has been relatively little experimental study. In large part this has been due to the absence of sensitive and efficient measuring techniques. The present study was concerned with an examination ofarelativelynewmeasure, "tube-dominance," in relation to two other tests of social behavior. Thus, three different behavioral measures were employed: (a) a test in which hungry Ss must push against each other in a narrow tube in order to reach food, (b) a test opposing hungry Ss in an arena containing a food aperture large enough for only one S at a time to eat, (c) a test of spontaneous fighting behavior. All three tests are standardized,easytoadminister, and employ objective behavioral measures. Each measure is believed on the basis of previous research to possess at least minimally adequate psychometric properties, and has been shown to possess sensitivity to behavioral differences between inbred strains of mice.The tube-dominance test was shown in a previous study (Lindzey, Winston, & Manosevitz, 1961) to be unusually reliable and to result in very stable transitive relationships both between individual Ss within groups and between different inbred strains of mice. One means of adding to our understanding of the psychological significance of the tube-dominance measure is to observe its relation to other measures of social behavior. More specifically, in the present study we were concerned with (1) the possibility that the three tests employed might be viewed as measures of the same general trait; (2) to observe the extent to which the genetically homogeneous Ss within inbred strains would perform in the same way on these measures; and (3) to determine for each measure the stability in performance over repeated trials between individual sets of opponents. Method Twenty-six male Ss were employed, organized into 13 matched pairs that remained the same for all three phases of testing. One member of each pair was from strain A, the other from strain DBA/8. Pairs were matched on the basis of age. Both strains have been inbred for more than 30 generations of brother-sister mating. All Ss were weaned and housed with same-sex littermates at 23 days of age, individually housed in metal cages at approximately 42 days, and were 75-100 days of age at the beginning of the experiment.The aggression test is a measure of spontaneous fighting betwe"n pairs of mice. The present apparatus and testing procedure is a Psychon. Sci., 1966, Vol. 5 (11) modification of that described by Fredericson (1...