Lykken D T, Bouchard T J, McGue M, Tellegen A
Department of Psychology, University of Minnesota, Minneapolis.
Acta Genet Med Gemellol (Roma). 1990;39(1):35-70. doi: 10.1017/s0001566000005572.
A birth-record based Registry is nearing completion of some 8,000 pairs of twins born in Minnesota from 1936 to 1955, plus some 1,200 pairs of male twins born 1971-81. The middle-aged twins were recruited with graded incentives so that ease of recruitment could be measured; it was found that pairs concordant for ease of recruitment were no more similar than discordant pairs in education, socioeconomic status (SES), or a variety of personality and interest factors, ie, that selection bias may not be a problem in research with adult twins when contacts are only by mail. A 50% decrease in neonatal mortality from 1936-55 to 1971-81 was associated with an increase from 3.5 to 4.0 per thousand in the frequency of viable MZ twin births. The broad heritability of SES, educational attainment, fecundity, and risk for divorce ranges from 0.30 to 0.50, although all 4 variables are plainly multifactorial and the latter 2 both involve variance contributed by a second person. Investigators interested in making use of this research resource are invited to submit proposals.
一个基于出生记录的登记处即将完成，该登记处涵盖了1936年至1955年在明尼苏达州出生的约8000对双胞胎，以及1971年至1981年出生的约1200对男性双胞胎。对中年双胞胎的招募采用了分级激励措施，以便衡量招募的难易程度；结果发现，在招募难易程度上一致的双胞胎在教育程度、社会经济地位（SES）或各种个性和兴趣因素方面并不比不一致的双胞胎更相似，也就是说，当仅通过邮件联系时，选择偏差在成年双胞胎研究中可能不是问题。1936 - 1955年至1971 - 1981年期间新生儿死亡率下降了50%，与存活的同卵双胞胎出生频率从每千例3.5例增加到4.0例相关。SES、教育程度、生育能力和离婚风险的广义遗传率在0.30至0.50之间，尽管所有这4个变量显然都是多因素的，并且后两个变量都涉及第二个人贡献的方差。欢迎有兴趣利用这一研究资源的研究人员提交提案。
