Furlow F B, Armijo-Prewitt T, Gangestad S W, Thornhill R
Department of Biology, University of New Mexico, Albuquerque 87131-1091, USA.
Proc Biol Sci. 1997 Jun 22;264(1383):823-9. doi: 10.1098/rspb.1997.0115.
Little is known about the genetic nature of human psychometric intelligence (IQ), but it is widely assumed that IQ's heritability is at loci for intelligence per se. We present evidence consistent with a hypothesis that interindividual IQ differences are partly due to heritable vulnerabilities to environmental sources of developmental stress, an indirect genetic mechanism for the heritability of IQ. Using fluctuating asymmetry (FA) of the body (the asymmetry resulting from errors in the development of normally symmetrical bilateral traits under stressful conditions), we estimated the relative developmental instability of 112 undergraduates and administered to them Cattell's culture fair intelligence test (CFIT). A subsequent replication on 128 students was performed. In both samples, FA correlated negatively and significantly with CFIT scores. We propose two non-mutually exclusive physiological explanations for this correlation. First, external body FA may correlate negatively with the developmental integrity of the brain. Second, individual energy budget allocations and/or low metabolic efficiency in high-FA individuals may lower IQ scores. We review the data on IQ in light of our findings and conclude that improving developmental quality may increase average IQ in future generations.
关于人类心理测量智力（智商）的遗传本质，我们所知甚少，但人们普遍认为智商的遗传性存在于智力本身的基因位点上。我们提出的证据与一个假设一致，即个体间智商差异部分归因于对发育压力环境源的遗传易感性，这是一种智商遗传性的间接遗传机制。利用身体的波动不对称性（FA，即在压力条件下正常对称双侧性状发育过程中出现错误所导致的不对称），我们估算了112名本科生的相对发育不稳定性，并对他们进行了卡特尔文化公平智力测验（CFIT）。随后对128名学生进行了重复实验。在两个样本中，FA与CFIT分数均呈显著负相关。我们针对这种相关性提出了两种并非相互排斥的生理学解释。第一，外部身体FA可能与大脑的发育完整性呈负相关。第二，高FA个体的个体能量预算分配和/或低代谢效率可能会降低智商分数。我们根据研究结果回顾了智商数据，并得出结论：改善发育质量可能会提高后代的平均智商。
