{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,17]],"date-time":"2025-09-17T16:46:45Z","timestamp":1758127605076},"reference-count":18,"publisher":"Cambridge University Press (CUP)","issue":"3","license":[{"start":{"date-parts":[[2008,7,31]],"date-time":"2008-07-31T00:00:00Z","timestamp":1217462400000},"content-version":"unspecified","delay-in-days":6605,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Biosoc. Sci."],"published-print":{"date-parts":[[1990,7]]},"abstract":"<jats:title>Summary<\/jats:title><jats:p>In a comparative study to examine the effect of social factors on human twinning, data on sociodemographic and other factors were collected from parents of all twins born alive in Denmark in 1984 or 1985 and from a random sample of parents of singleton infants born in the same years. A postal questionnaire was used. The twins were classified as monozygotic (MZ) or dizygotic (DZ) twins by the similarity method. A trend was found in DZ-twinning, with significantly fewer DZ-twins born in the lower social classes, but not in MZ-twinning. All results were controlled for maternal age and parity.<\/jats:p>","DOI":"10.1017\/s0021932000018745","type":"journal-article","created":{"date-parts":[[2008,7,31]],"date-time":"2008-07-31T12:04:13Z","timestamp":1217505853000},"page":"381-386","source":"Crossref","is-referenced-by-count":3,"title":["Social class and human twinning"],"prefix":"10.1017","volume":"22","author":[{"given":"Birgitte","family":"B\u00f8nnelykke","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"56","published-online":{"date-parts":[[2008,7,31]]},"reference":[{"key":"S0021932000018745_ref018","doi-asserted-by":"publisher","DOI":"10.1002\/ajpa.1330090405"},{"key":"S0021932000018745_ref017","volume-title":"Observations on the Determinants of Human Multiple Birth","author":"Smith","year":"1974"},{"key":"S0021932000018745_ref013","doi-asserted-by":"publisher","DOI":"10.1093\/oxfordjournals.jhered.a105142"},{"key":"S0021932000018745_ref011","first-page":"410","article-title":"Secular changes in rates of multiple births in the United States","volume":"14","author":"Jeanneret","year":"1962","journal-title":"Am. 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