Historically, some societies around the world killed newborn twins, though
the practice was forsaken in the early twentieth century. Anthropologists have proposed
different theses: (1) the delivery of twins occurred when the mother cheated on her
husband, or committed a great sin, and killing the twins was the penalty, (2) twinkilling
was done to assert that human beings were different from animals among
which multiple births in the same delivery were seen, (3) twins brought a dilemma to
the kinship structure of societies and to cope with it different rules were adopted, twinkilling
being the extreme one, (4) twin-killing was a means to face resource stress. We
argue that although those interpretations are useful, we can improve the understanding
of that phenomenon by adding an identity economics model, where twins are a taboo.
Identity economics helps us explain the persistence of the practice and its eventual
decline. We make our case with examples from the Igbo of Nigeria.

• Twin-killing in some traditional societies: an economic perspective