Twin Research in Ethological and Evolutionary Perspective /: News and Views from the International Society for Human Ethology / Twin Research Summaries: Parthenogenetic 46, XX/46, XY Congenital Chimera; Parental Favoritism of One Twin; Parasitic Twins; Twin Study of Primal World Beliefs / Human Interest: Twins’ Matching Lives; Birth of Three Triplet Sets; Chinese Twins Reared Apart; Conjoined Twin Separation

The functional significance of monozygotic and dizygotic twinning is explored. The specific question of why twinning is maintained in human populations, despite the risks to mothers and infants, will be addressed. Next, summaries of recent and current research will be presented. The topics cover congenital chimerism, parental favoritism toward one twin, parasitic twins, and a twin study of primal world beliefs. In the final section of this essay a variety of informative general interest stories are considered. They include twins' matching lives; the birth of three triplet sets; a pair of Chinese reared-apart twins; and a landmark conjoined twin separation.