I think a person can be conditioned to behave certain ways. Personality is likely formed at a young age. Genotype contribute to trait expression. The genes coding for personality exists as a network at the start of life. The blueprint comes from both parents.

In the first months, the basis of the network or the subconscious is further formed at the same time babies learn basic motor function. In the early years, children socialise and a set of learned behavious forms. By adolescence people are set in their ways. They make important decisions that could affect the rest of their lives.

Adult personality include traits inherited from parents. How the person makes decisions is based on events that influenced them in the past.