Persistent bias in expert judgments about free will and moral responsibility: A test of the expertise defense

► Documents bias in expert judgments about free will and moral responsibility. ► Challenges the expertise defense used to insulate philosophers' reasoning. ► Shows that bias is predicted by a heritable personality trait (i.e., extraversion). ► Introduces a reliable, validated test of expert knowledge in free will debates. ► Implications for the practice of philosophy and professional ethics (law, medicine).