ABSTRACT
Litters of offspring among animals must have been a familiar phenomenon to our nomadic and agricultural ancestors; hence multiple births (MBs) among humans cannot have been a surprising or mysterious occurrence. Nevertheless, twins figure as special human beings in myth and literature, and interest in them goes back as far as recorded history. The Bible tells of Jacob and Esau, who presumably were fraternal twins, since they displayed different physical characteristics (Esau being hairy and Jacob smooth). Greek mythology tells of Castor and Pollux, who form the Gemini constellation in the sky. Rome had its mythical twin founders: Romulus and Remus. Twins also figure in much of literature, from a Plautus comedy to Shakespeare to Thornton Wilder’s (himself a twin) The Bridge of San Luis Rey.
