Nativism in the field of psychology believes that some abilities of the individual is present by birth. The nativism theory was first supported by the John Locke and David Hume.
The nativism believes that Humans have inborn talent or some qualites by birth. Peter has idea that the walking ability is already present by birth and individual known the walking style difference by birth.
In psychology, the nativist theory suggests that the abilities and the skills in the newborn babies are hard-wired or is present from birth. The skills and the abilities of the babies are native sue to the innate structures formed in the brain from birth and is least influenced by the experience.
In the given question, since the peter believes that the child can understand the difference between the two actions, therefore, he believed in the Theory of nativism.
Thus, The theory of Nativism is the correct answer.
Just because you have a certain body type doesn't mean that you are not who you identify as. Even if you have a more feminine body, you can still identify as a male. Surgery is not what makes you transgender. Hope my explanation helped
