Answer
Introjection, as conceptualized by Karen Horney, refers to the unconscious adoption and assimilation of the characteristics, behaviors, and attitudes of others into one's own personality. It is a defense mechanism employed to cope with feelings of insecurity and anxiety, as individuals unconsciously internalize traits they perceive as desirable or protective from external threats. This psychological process contributes to the formation of an individual's self-concept and interpersonal dynamics.