Psychopathology is the study of abnormal cognition, behaviour, and experiences which differs according to social norms and rests upon a number of constructs that are deemed to be the social norm at any particular era. Biological psychopathology is the study of the biological etiology of abnormal cognitions, behaviour and experiences. Child psychopathology is a specialisation applied to children and adolescents. Animal psychopathology is a specialisation applied to non-human animals. This concept is linked to the philosophical ideas first outlined by Galton (1869) and is linked to the appliance of eugenical ideations around what constitutes the human.