Introduction

Kin recognition, especially the failure to recognize close relatives, is a commonly occurring theme in the history and literature of western civilization. Sophocles' tragic tale of Oedipus is perhaps the best known example of kin recognition gone awry. Oedipus followed the inadvertent murder of his father (Laius) by unknowingly marrying his own mother (Jocasta). According to the Old Testament (Genesis 27:27) an error in kin discrimination enabled Jacob to cheat his older brother Esau out of his birthright. By disguising himself as Esau, Jacob deceived their father (Isaac) into granting him the final blessing and inheritance intended for the first born son. Similarly, the fate of Odysseus (Ulysses) was ultimately decided by his inability to identify one of his offspring. On his final voyage, Odysseus launched an attack against Telegonus – his son born of the goddess Circe. Only after being mortally wounded by the younger man did the hero of Homer's saga learn of their relationship.

Despite such long-held fascination with the consequences of kin recognition errors, humans are evidently quite proficient at recognizing family members (as well as other individuals). Nonetheless, there is little knowledge of the scope of human kin recognition capabilities or the underlying bases of this form of social discrimination. As recently pointed out by Wells (1987), in comparison to research with various non-human species, there have been relatively few empirical studies of kin recognition in our own species.