{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T09:44:23Z","timestamp":1791884663444,"version":"4.3.4"},"reference-count":23,"publisher":"Cambridge University Press (CUP)","issue":"4","license":[{"start":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T00:00:00Z","timestamp":1785888000000},"content-version":"unspecified","delay-in-days":4,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":["cambridge.org"],"crossmark-restriction":true},"short-container-title":["Twin Res Hum Genet"],"published-print":{"date-parts":[[2026,8]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>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\u2019 matching lives; the birth of three triplet sets; a pair of Chinese reared-apart twins; and a landmark conjoined twin separation.<\/jats:p>","DOI":"10.1017\/thg.2026.10091","type":"journal-article","created":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T10:15:24Z","timestamp":1785924924000},"page":"390-393","update-policy":"https:\/\/doi.org\/10.1017\/policypage","source":"Crossref","is-referenced-by-count":0,"title":["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\u2019 Matching Lives; Birth of Three Triplet Sets; Chinese Twins Reared Apart; Conjoined Twin Separation"],"prefix":"10.1017","volume":"29","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9303-8312","authenticated-orcid":false,"given":"Nancy","family":"Segal","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02avqqw26","id-type":"ROR","asserted-by":"publisher"}],"name":"California State University Fullerton"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"56","published-online":{"date-parts":[[2026,8,5]]},"reference":[{"key":"S1832427426100917_ref2","doi-asserted-by":"publisher","DOI":"10.1017\/S002193209900245X"},{"key":"S1832427426100917_ref23","doi-asserted-by":"publisher","DOI":"10.1038\/s42003-020-01372-8"},{"key":"S1832427426100917_ref13","first-page":"1","article-title":"Parental differential treatment and symptoms of child psychopathology: A twin study","volume":"5,","author":"Maravilla","year":"2026","journal-title":"Development and Psychopathology"},{"key":"S1832427426100917_ref18","doi-asserted-by":"publisher","DOI":"10.4159\/harvard.9780674065154"},{"key":"S1832427426100917_ref20","doi-asserted-by":"publisher","DOI":"10.1016\/j.earlhumdev.2023.105903"},{"key":"S1832427426100917_ref5","article-title":"Twins conjoined at the head separated after 40 hours in \u2018landmark\u2019 surgery","author":"England","year":"2026","journal-title":"People Magazine."},{"key":"S1832427426100917_ref16","doi-asserted-by":"publisher","DOI":"10.1016\/S0169-5347(97)01179-8"},{"key":"S1832427426100917_ref11","article-title":"The weird rise of people who are their own twin","author":"Leach","year":"2026","journal-title":"Science Focus (BBC)"},{"key":"S1832427426100917_ref9","doi-asserted-by":"publisher","DOI":"10.1007\/s11692-019-09470-0"},{"key":"S1832427426100917_ref3","article-title":"Baby boom! Triplets are taking over and setting records at Pennsylvania Hospital","author":"Colosi","year":"2026","journal-title":"Today"},{"key":"S1832427426100917_ref12","doi-asserted-by":"publisher","DOI":"10.1097\/SCS.0000000000012057"},{"key":"S1832427426100917_ref21","doi-asserted-by":"publisher","DOI":"10.1016\/j.paid.2024.112751"},{"key":"S1832427426100917_ref7","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.91.24.11363"},{"key":"S1832427426100917_ref15","first-page":"765","volume":"59","author":"Pison","year":"2004","journal-title":"Population"},{"key":"S1832427426100917_ref14","doi-asserted-by":"publisher","DOI":"10.1080\/17439760.2024.2387340"},{"key":"S1832427426100917_ref6","doi-asserted-by":"publisher","DOI":"10.1016\/j.fsigen.2025.103394"},{"key":"S1832427426100917_ref4","doi-asserted-by":"publisher","DOI":"10.1017\/S0140525X00060416"},{"key":"S1832427426100917_ref10","unstructured":"Kantor, W. G. (2026, June 12). lifelong friends discover they\u2019re actually \u2018identical mirror\u2019 twins. Their parents cared more than they did (Exclusive). People Magazine. https:\/\/people.com\/friends-always-celebrated-shared-birthday-then-they-learn-they-are-twins-11993153"},{"key":"S1832427426100917_ref22","article-title":"Twins, 82, wear identical outfits and have never lived or worked apart. Now, they\u2019ve just undergone the same surgery together","author":"Sheffield","year":"2026","journal-title":"People Magazine."},{"key":"S1832427426100917_ref17","volume-title":"Entwined lives: Twins and what they tell us about human behavior","author":"Segal","year":"2000"},{"key":"S1832427426100917_ref19","volume-title":"Twin mythconceptions: False beliefs, fables, and facts about twins","author":"Segal","year":"2017"},{"key":"S1832427426100917_ref8","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/den305"},{"key":"S1832427426100917_ref1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1558-5646.1990.tb05211.x"}],"container-title":["Twin Research and Human Genetics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S1832427426100917","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T08:44:29Z","timestamp":1791881069000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S1832427426100917\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8]]},"references-count":23,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2026,8]]}},"alternative-id":["S1832427426100917"],"URL":"https:\/\/doi.org\/10.1017\/thg.2026.10091","relation":{},"ISSN":["1832-4274","1839-2628"],"issn-type":[{"value":"1832-4274","type":"print"},{"value":"1839-2628","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8]]},"assertion":[{"value":"\u00a9 The Author(s), 2026. Published by Cambridge University Press on behalf of International Society for Twin Studies","name":"copyright","label":"Copyright","group":{"name":"copyright_and_licensing","label":"Copyright and Licensing"}}]}}