Determined, but influenced by inheritance. No one is born the way they will remain for the rest of their lives. Take certain mental illnesses such as Bi-Polar Disorder as an example. This is hereditary and rarely skips a generation. Having Bi-Polar Disorder will influence a person's personality, and make them more susceptible to certain traits, but all can be changed based on a person's own experiences. Behavioral modification therapy, an environmental solution and factor, can change and manage even the most stubborn or disruptive of personality traits. People become what their experiences, society, wealth, interests and environment dictate, but their hereditary traits will play a part as well.
Excellent post, buddy. It reminds of the writings by Esyneck who theorized that humans are unique in that they are biosocial entities that are born with specific predispositions in how they respond to a situation. It is interesting that you pointed out how Bi-Polar disorder is an example of a genetic predisposition does directly influence personality. And concerning Schizophrenia, two genes , the CTCF and the CACNB2 genes being mutated does in fact lead to the development of schizophrenia as these genes experience polymorphism in schizophrenics, whereas in non-schizophrenics its not. This then leads Neuroscientists , Neuropsychologists to premise that there must be some kind of excision repair malformation wherein it has led to the improper removal of developed dimers.
But it is interesting to note that there is a direct genetic correlation with personality in the case of Schizophrenics, as well as those who have Alzheimer's Disease.
