instinctual

/ɪnˈstɪŋktʃuəl/
adjective
  1. Relating to or based on instinct; arising from natural impulse rather than thought.
    • His instinctual fear of heights kept him away from the cliff edge.
    • Many human emotions have an instinctual basis.
    • The animal's instinctual behavior is triggered by the changing seasons.