They are saying all your decisions that appear to be free will are actually made due to previously-existing causes and conditions in your life.
This is why it is said that someone conditioned to live in a ghetto can be removed from the ghetto but the ghetto can never be fully removed from within them.
If you were raised not to hit women you won't, and you will say it's due to your free will. If you were raised to hit women you will, and say it's due to your free will.