Social Dominance Test Tube SDT, without partitions, model M30210 is manufactured by Yuyan Instrument Co., Ltd. The Social Dominance Tube Test is a behavioral experiment that studies whether rats or mice occupy dominant or submissive positions in social groups. By observing and recording parameters such as the number of times two mice successfully occupy the "shared space" in the cylindrical tube, their social dominance and social class status can be reflected. Of course, sometimes two animals have equal status and share the "public area" equally.