Nature is the heritable part nurture is the "seems easiest to change" part. Of course turns out that gene-environment interactions are common and complicated,

Nature is the heritable part nurture is the "seems easiest to change" part. Of course turns out that gene-environment interactions are common and complicated, so most of the things are mixed. Brain development takes about 20 years, driven by genes, but the environment is extremely important to help people to learn how to get most out of that setup they got. This is most evident in learning disabilities, for example stimulants are regularly described as life-changing by ADHD folks.