Not only parenting: genes, temperament, and why care still matters in : the main line · 299

Temperament — reactivity, soothability, approach or withdrawal, persistence — shows early and is moderately stable. Twin and adoption studies find substantial heritability for many behavioural traits, though estimates vary by trait, age and method. Innate does not mean fixed or immune to experience. It means the child brings a starting bias into every interaction. Two siblings in the same home can live different emotional climates because their nervous systems sample the world differently.

Parenting is not the whole cause — and still not optional When outcomes track genes and peers as well as home life, parents are relieved of omnipotence — and of total blame. That relief is healthy. It does not license neglect. Sensitive care, predictable limits and protected sleep still predict better regulation and safer relationships across many studies.

Think of caregiving as a volume and filter: it rarely invents a trait from nothing, but it can amplify, buffer or channel what is already there. A highly reactive child in a harsh, chaotic home is not the same developmental experiment as that child in a calm, structured one. Gene–environment interplay, without the slogans