Children vary in their developmental plasticity. Those most vulnerable to the negative effects of adversity are also the most likely to benefit from supportive environments. Conversely, children who are resilient in the face of hardship are often less susceptible to the positive effects of enrichment and nurturance.
In restrictive environments where choices are limited, genetics play a smaller role in life outcomes. As society provides more opportunity and information—for example, in education for women or food availability—individual genetic predispositions become more significant differentiators, leading to genetically-driven inequality.
Contrary to viewing adversity's effects as mere dysfunction, an evolutionary lens suggests they are adaptations. For example, accelerated puberty in response to a threatening environment increases the chances of passing on genes, prioritizing reproduction over long-term health, neatly summarized as 'live fast and die young.'
People tend to marry and befriend those who are genetically similar, a process that amplifies genetic inequality in the next generation. This is compounded by geographic sorting, where individuals with genetic propensities for success migrate away from disadvantaged areas, leaving them 'doubly disadvantaged, genetically and environmentally.'
The Polygenic Index (PGI) summarizes thousands of minor genetic effects into a single predictive score for complex outcomes like educational attainment or heart disease. This 'age of genomic prediction' will radically alter social domains like insurance, education, and even embryo selection, creating profound ethical challenges.
Your outcomes are influenced not just by your own DNA but by the genes of those in your social environment, a concept called 'genetic nurture.' A spouse’s genes can affect your likelihood of depression, and a child's genes can evoke specific parenting behaviors, showing that the effect of genes doesn't stop at our own skin.