Answer:
The answer is a combination of both, however the basis of which your personality is formed comes from genetics.
Step-by-step explanation:
While it is true that a person's environment shapes them over time, a foundation of each individual is passed on genetically from one generation to the next. The best apology to use is that our genetics make our personality a block of clay and the environment turns us into what we are. with that being said our personality at its deepest roots, is genetics, while the evolution of that personality is all environment.