Instinctual refers to something that is happening naturally, as a result of instinct, rather than being thought about, planned, or developed by training. It is a largely inheritable and unalterable tendency of an organism to make a complex and specific response to environmental stimuli without involving reason. Instinctual behavior is mediated by reactions below the conscious level. Synonyms for instinctual include automatic, instinctive, and involuntary. ^{cambridge.org 1 2 3}