This table represents a serious challenge to traditional theories in psychology. Individual differences are largely a product of genes (A) and the non-shared environment (ENS). The shared family environment (ES) often has surprisingly little impact.
Nature, Nurture, and Random Chance: The two biggest factors shaping individual differences are genes and developmental noise. (!) See also 's book #Innate
Another paper makes the case that the "non-shared environment", the great unknown of behavioral genetics, may be largely traceable to chance events during prenatal development. More: Why children in the same family are so different
Population health scientists, behavioural geneticists (and even geneticists who can't behave, like ) should stop referring to the "non-shared environment" - it is a completely incorrect and confusing term. For a great recent read on this (££)
Nature x nurture x noise. Intrinsic stochasticity (or internal non-shared environment (NSE)) as key source of phenotypic variation
Havent read this but looks interesting & given the rise of behavioural genetics in companion animals will also b relevant to discussion of behavioural traits there (stochasticity of molecular mechanisms likely explains much of the variation within breeds)
But the very first sentence is false. If one measures personality poorly, as by self-report only, then one gets that result. But proper measurements of personality and their extension into psychiatric problems usually finds higher heritabilities.