Qu'est-ce qu'un instinct? Qu'est-ce qu'un instinct? An inborn pattern of behavior that is characteristic of a species and is often a response to specific environmental stimuli: the spawning instinct in salmon; altruistic instincts in social animals. A powerful motivation or impulse.An innate capability or aptitude: an instinct for tact and diplomacy. Deeply filled or imbued: words instinct with love. Obsolete Impelled from within.