Ethology is defined as comparative study of Behaviours. The proceeding for a human ethology would consist in watching the psychopathologic phenomenon, as a natural happening, without modifying it by observer's presence. Then, in analysing this fact according to methods suggested from physiology. Ethological observation reveals a psychopathological fact about little chimpanzees in maternal deficiency: disturbance in directions for using the world and understanding rituals of communication. The experimental analysis of the fact puts forward notions of anxiolytic power of mother's bodily touch, during a fertile period of S.N.C. maturation. This leak produces in grown-up, emotional disturbances with exploration activities directed to his own body. But the group offers maternal substitute possibility in bringing an available satisfaction to the psychophysiological exigences. Chiefly, the ethological proceeding applied to the little Human leads to comparable conclusions, opening perhaps, experimental era of psychology of the Unconscious.