Department of Psychology, Program in Behavioral and Systems Neuroscience, Rutgers University.
Psychol Bull. 2018 Jan;144(1):26-47. doi: 10.1037/bul0000131. Epub 2017 Oct 30.
Intelligence can have an extremely high heritability, but also be malleable; a paradox that has been the source of continuous controversy. Here we attempt to clarify the issue, and advance a frequently overlooked solution to the paradox: Intelligence is a trait with unusual properties that create a large reservoir of hidden gene-environment (GE) networks, allowing for the contribution of high genetic and environmental influences on individual differences in IQ. GE interplay is difficult to specify with current methods, and is underestimated in standard metrics of heritability (thus inflating estimates of "genetic" effects). We describe empirical evidence for GE interplay in intelligence, with malleability existing on top of heritability. The evidence covers cognitive gains consequent to adoption/immigration, changes in IQ's heritability across life span and socioeconomic status, gains in IQ over time consequent to societal development (the Flynn effect), the slowdown of age-related cognitive decline, and the gains in intelligence from early education. The GE solution has novel implications for enduring problems, including our inability to identify intelligence-related genes (also known as IQ's "missing heritability"), and the loss of initial benefits from early intervention programs (such as "Head Start"). The GE solution can be a powerful guide to future research, and may also aid policies to overcome barriers to the development of intelligence, particularly in impoverished and underprivileged populations. (PsycINFO Database Record
智力具有极高的遗传性，但也具有可塑性；这一悖论一直是持续争论的根源。在这里，我们试图澄清这个问题，并提出一个经常被忽视的悖论解决方案：智力是一种具有特殊性质的特征，它创造了大量隐藏的基因-环境（GE）网络，从而使高遗传和环境因素对个体智商差异产生影响。目前的方法很难具体说明 GE 相互作用，而且在遗传力的标准指标中被低估（从而夸大了“遗传”效应的估计）。我们描述了智力中 GE 相互作用的实证证据，可塑性能在遗传性之上存在。这些证据涵盖了因收养/移民而导致的认知增益、智商在整个生命周期和社会经济地位中的遗传性变化、社会发展导致的智商增长（弗林效应）、认知衰退随年龄增长的放缓，以及早期教育带来的智力提升。GE 解决方案对持久存在的问题具有新的意义，包括我们无法识别与智力相关的基因（也称为智商的“缺失遗传力”），以及早期干预计划（如“开端计划”）最初收益的丧失。GE 解决方案可以成为未来研究的有力指南，也可能有助于克服智力发展障碍的政策，特别是在贫困和弱势群体中。
