Patient compliance is the degree to which a person adheres to the professional advice healthcare providers offer. Aside from significantly compromising a person’s health, non-compliance also wastes resources and productivity. The monetary costs of medical noncompliance has been estimated to be around $300 billion a year. Demographic, disease severity and gender effects on compliance are small. In dental hygiene, where practitioners focus on the prevention of oral disease, motivating patients to practice healthy behaviors has long been a challenging, and often frustrating, aspect of practice. Any discussion of compliance must begin with a brief review of human development and the factors which shape our personalities. Once we recognize the conscious and unconscious forces which control human behavior we can better understand the motivation behind our patient’s actions. Or, more often, their inactions.