Nativists and empiricists believe that development is primarily effected by nature and nurture respectively, and debate the famous nature-versus-nurture question regarding development (Santrock, 2019). A nativist is someone who claims that the environment has had little influence on who you are, inferring that you are biologically predisposed to be who you are. Scientifically speaking, their argument is well-founded (Santrock, 2019). When born, we have our own unique set of DNA, that determines our genotype (or genetic characteristics), and therefore play a large role in how our brains are formed in utero (Santrock, 2019). When the genetic coding goes awry, and the mutations result in genetic abnormalities (down syndrome, fragile syndrome, spina bifida, Huntington's disease, etc.), the people with these abnormalities have different levels of brain development and may access their intelligence differently than those born with normal genes (Santrock, 2019, p. 59-60). When thinking about genetics, a nativist may strongly believe in the power of the "active genotype-environment correlation," in which people tend to seek out environments that support their genotype's ingrown strengths (Santrock, 2019). For example, children that are physically intelligent will seek environments in which they can strive physically.
However, much of intelligence can also be attributed to environment. Though we may witness physically intelligent people in physically intensive environments, the answer may not all lie in the genetics. In circus families for example, it is debatable whether the children inherit their physical intelligence from their parents genetically, or whether it comes from training many hours from a young age, stimulating their motor development. The "passive genotype-environment correlations" speak to this, suggesting that if parents are drawn towards circus, they are likely to live a lifestyle in which they are physically active often and in which they engage in physical activities with their children (Santrock, 2019, p. 68). The children are therefore more likely be physically adept.
Twins are great examples when discussing nature vs. nurture. My twin sister and I are the same race, size, sex, class, age, and were raised with the same environmental factors from utero through the first 10 years of our lives. Though we are very similar on many levels, we are also notably different. We have different energies, sensibilities and intelligences that, according to my mother, were palpable from the moment that we were born.
Gottelieb's epigenetic view proposes that nature and nurture collaborate continuously throughout our lives to form us as people (Santrock, 2019). For example, a child who is genetically predisposed to have a sugar addiction may have emotional repercussions or not depending on if they are raised in an environment with or without sugar. In an average family in the US, the child may suffer obesity, depression, and their temperament may be affected greatly. However, if raised in the Amazonian jungle, the child may be incredibly high functioning and happy. The environment would change the child's experience of life. Yet if they were not predisposed genetically to react poorly to sugar, the environments may not make much of a difference on the child in these ways. Both environment and heredity play a role, resulting in a "bidirectional interchange" (Santrock, 2019, p. 69).
Santrock, J. W. (2019). Lifespan development (17th ed.). New York: McGraw-Hill.