Heredity and environment become the blinders that keep them plodding faithfully along their track of karma. Free will is involved in the selection of the action taken. Karma is involved in creating the circumstances that make selecting an action necessary. Evolution and spiritual growth in joy, love, and awareness are the end results of the karmic process. When you recognize that your physical body is merely one of the garments your Soul wears to gain experience, you can understand how to transcend your circumstances.
Every problem contains the solution within it.
All physical, mental, or emotional environments experienced within this lifetime can also be transcended. The media is full of stories about how certain individuals have overcome incredible odds. Doing so, necessarily involves working on your emotions. It is your emotions that drive you to take action to resolve the causes and effects of your heredity and environment. Karma perates impersonally, giving you the opportunity at every moment to become open to greater levels of love and compassion.