Many illustrations are brought together in Gesell's study of "Jealousy."
Jealousy among lower races may be disguised or modified by tribal customs. Thus Rasmussen (People of the Polar North, p. 65) says in reference to the Eskimo custom of wife-exchange: "A man once told me that he only beat his wife when she would not receive other men. She would have nothing to do with anyone but him—and that was her only failing!" Rasmussen elsewhere shows that the Eskimo are capable of extreme jealousy.
See, e.g., Moll, Sexualleben des Kindes, p. 158; cf., Gesell's "Study of Jealousy."
Jealousy is notoriously common among drunkards. As K. Birnbaum points out ("Das Sexualleben der Alkokolisten," Sexual-Probleme, Jan., 1909), this jealousy is, in most cases, more or less well-founded, for the wife, disgusted with her husband, naturally seeks sympathy and companionship elsewhere. Alcoholic jealousy, however, goes far beyond its basis of support in fact, and is entangled with delusions and hallucinations. (See e.g., G. Dumas, "La Logique d'un Dément," Revue Philosophique, Feb., 1908; also Stefanowski, "Morbid Jealousy," Alienist and Neurologist, July, 1893.)