This chapter discusses how the brain learns to associate sexual arousal and reward with certain stimuli through experiences and repetition during youth and adulthood. This leads to the formation of neural pathways that label certain people, acts, or objects as sexually arousing. While evolution plays a role, much of what people find attractive is acquired and learned rather than innate. Repeated viewing of pornography trains the brain to see it as arousing and rewarding due to the potent neurochemical cocktail released during masturbation and orgasm. This strengthens the attachment and addiction to porn.