The desire for sexual expression varies greatly from one individual to another. A person's desire for sexual expression is influenced by a multitude of factors, ranging from feelings of attractiveness, the availability of a partner, level of personal power, economics, cultural attitudes, genetics, religious beliefs, age, level of health, and gender. Research reports have documented that humans have the capacity to enjoy and engage in sexual activity throughout their lives. Almost all human beings express themselves sexually (ranging from several times a day to only a few times in a lifetime) through masturbation, intercourse, and a variety of other activities, depending on their level of desire and the other factors that influence their behavior. The desire component of sexuality has been incorporated into alternate models of the sexual response cycle by several researchers. One model describes four phases, beginning with desire, combines the excitement and plateau phases, and includes orgasm and resolution, while another five-phase model includes desire, arousal, physiological readiness, orgasm, and satisfaction. A third model combines the physiological and psychological dimensions of sexual response by overlapping the four-phase model with the psychological components of seduction, sensations, surrender, and reflection.