Johnson Wendy, Hicks Brian M, McGue Matt, Iacono William G
Department of Psychology, University of Edinburgh, Scotland, United Kingdom.
Intelligence. 2009 Nov 1;37(6):613-624. doi: 10.1016/j.intell.2008.12.003.
In old and even middle age, there are associations between physical health and both intelligence and education. This may occur because intelligence and/or education exert effects on lifestyle choices that, in turn, affect later health. Substance use is one aspect of lifestyle choice in young adulthood that could play such a role. The effects of intelligence and/or education on substance use could be direct and environmental, or indirect due to the presence of confounding genetic and shared family influences. We used the Minnesota Twin Family Study to distinguish these effects in males and females at age 24. In contrast to prevailing expectations, there were moderately negative direct nonshared environmental effects of both IQ and education on both smoking and drinking in both males and females. That is, controlling for positive family background effects in the form of both genetic and shared environmental influences, both higher IQ and greater education were associated with greater alcohol and nicotine use. These effects were accounted for by alcohol and nicotine use at age 17. Our results suggest that genetic and family-culture variables confound the associations between intelligence and education and substance use in young adults, rendering them indirect. Further research is needed to understand the roles of IQ and education in alcohol and nicotine use and their relative impacts on physical health throughout the lifespan.
在老年甚至中年时期，身体健康与智力和教育之间存在关联。这种情况可能发生，是因为智力和/或教育会对生活方式的选择产生影响，而生活方式的选择反过来又会影响后期的健康。物质使用是青年期生活方式选择的一个方面，它可能起到这样的作用。智力和/或教育对物质使用的影响可能是直接的环境影响，也可能是由于存在混杂的遗传和家庭共同影响而产生的间接影响。我们利用明尼苏达双生子家庭研究来区分24岁男性和女性中的这些影响。与普遍预期相反，智商和教育对男性和女性的吸烟和饮酒都有适度的负面直接非共享环境影响。也就是说，在以遗传和共享环境影响形式存在的积极家庭背景影响得到控制的情况下，较高的智商和较高的教育水平都与更多的酒精和尼古丁使用有关。这些影响可以由17岁时的酒精和尼古丁使用来解释。我们的结果表明，遗传和家庭文化变量混淆了年轻人中智力、教育与物质使用之间的关联，使其成为间接关联。需要进一步的研究来了解智商和教育在酒精和尼古丁使用中的作用，以及它们在整个生命周期中对身体健康的相对影响。
