Final answer:
Factor 3: Lifestyle incorporates characteristics such as irresponsibility, excessive need for stimulation, and lack of planning and realistic goal-setting.
Step-by-step explanation:
The core behavioral dimension or "factor" of psychopathy that incorporates characteristics such as irresponsibility, excessive need for stimulation, and lack of planning and realistic goal-setting is Factor 3: Lifestyle.
This factor in the Five Factor Model of personality is associated with a reckless and impulsive lifestyle, where individuals engage in irresponsible behaviors, seek constant excitement, and lack long-term planning and goal-setting.
References:
Cattell, R. B. (1957). The personality sphere and the personality structure. In Handbook of Personality Theory and Research (pp. 47-78).