Criminological theories are often complementary, rather than standalone concepts. Theories such as rational choice, deterrence, and opportunity theory can be employed in conjunction with one another to challenge, build upon, and affirm or contradict each other. Where one theory might leave a gap, the use of additional theories can fill that gap. Criminal behavior is not necessarily always simple and straightforward, and in many cases more than one theory can relate to a particular crime. In fact, the one-dimensional approach to explaining crime often tends to be inadequate because it ignores more factors than it takes into account (Barak). As a result, integrative or interdisciplinary theories of crime are coming into wider use (Barak). An understanding of the fundamental traditional theories, as well as a perspective on seeing them in combination, provides a more comprehensive approach to examining criminal behavior.
Rational choice theory is one of the most widely used theories in criminology. This theory assumes that people have the freedom to choose what behaviors they engage in, and that they make those choices based on rational calculations that take into consideration the potential pleasure or pain that the consequences of their actions will entail (Keel). Naturally, most people choose actions that they believe will maximize their pleasure rather than their pain, so punishment for crimes committedùparticularly swift, severe, and certain punishmentùis essential for controlling human behavior (Keel).
Labeling theory asserts that when labels are applied to people, those labels influence their behavior ("Labeling theory"). Negative, or stigmatizing, labels such as "criminal" can become self-fulfilling prophecies, as they actually promote the deviant behavior that characterizes the label ("Labeling theory"). This theory posits that the offenders can be rehabilitated by changing the labels ("Labeling theory").