Biological Theories and Criminal Behavior
Biological theories address deviant behavior as a relationship between biological factors, and social norms in respect to crime. The theories address behavior of an individual based upon his or her biological impact. Schmalleger, (2008) points out a connection to social environments and the impact upon human behavior. The connection has validity because of human thoughts and activities are constantly flowing through the brain providing an impact relating to behavior. Researchers base biological theories on flaws relating to heredity, dysfunction of the brain’s neurotransmitters, injuries, trauma, or abnormalities involving the brain affecting behavior (Raine, 2002).
Brain development is a biological theory providing information connecting damage of the frontal lobes located in the brain’s cerebrum to criminal behavior. The brain is similar to a computer sending messages to the body and when the messages cannot be delivered it is because of a dysfunction that has occurred in the brain. The frontal lobes and the limbic system are two of the major areas of the brain involving behavior. The frontal lobes are responsible for reasoning, problem solving, and emotions (Allen & Harper, 2010). The limbic system contains electrical circuitry controlling emotions and motivation (Allen & Harper, 2010). The amygdala when stimulated produces behavior related to emotions, memory and fear. When the amygdala is functioning properly it produces the proper behavioral reaction or response to the event that is happening (Allen & Harper, 2010)
When damage occurs to the frontal lobes the ability to reason or censor thoughts, and actions will become impaired leading to maladaptive behavior, aggression, or anti-social behavior (Allen, & Harper, 2010). A study by Antonio Damasio provided information relating to injuries of the frontal lobes may be responsible for anti- social behavior (Crime Times, 2007). The study revealed that damage to the frontal lobes was evident when monitoring the individuals who were injured when he or she exhibited social skills and behavior (Phillips, 2012). Patients who were able to handle and deal with decisions previously in his or her personal life were no longer able to do so (Phillips, 2012). Intellectually there was no change but when he or she had to make a decision involving emotions and feelings the abnormalities in behavior were exhibited (Phillips, 2012). Phineas Gage is the major example relating to the damage to the frontal lobes and change in behavior. He worked as a foreman on the railroad engaged in construction work. There was an explosion when the tampering rod he was using ignited the blasting powder and the tampering rod entered his head just below the jaw traveling through the frontal lobe of his brain exiting the top of his head. After the initial recovery he began to exhibit violent, aggressive, and anti-social behavior (Crime Times, 2007). Phineas Gage was a mild mannered individual prior to his accident but after the injury to the frontal lobe he became just the opposite a man exhibiting aggression and anti-social behavior. The inability to make rational decisions, control aggression, and emotions has a possible connection to criminal thoughts and behavior. Ongoing research relating to the connection of crime and brain dysfunction will perhaps provide a more solid explanation in the near future.
Neuropsychological factors may interfere with the ability to make important functional and executive decisions on a daily basis (Bartol & Bartol, 2011). Abnormalities in the brain may increase the aggression while preventing the ability to control aggressive behavior (Bartol & Bartol, 2011). The central nervous system provides a route for electrical impulses relating to thought, behavior, and emotions traveling to and from the brain. Synapses are the gaps between the cells of the nervous system and chemicals known as neurotransmitters provide the impulses the means of connecting to the synapses (Allen & Harper, 2010). When electrical impulses are interrupted researchers believe it is the result of low levels of neurotransmitters that interfere with emotions and produce aggressive behavior. Serotonin is a neurotransmitter and when the levels drop there is a proven relationship between violence and behavior (Allen & Harper, 2010). The anti-social behavior and chemical imbalances are prevalent in alcoholics. Malnutrition in children also inhibits the growth and development of the brain. Cognitive deficiencies and underdeveloped brains place children and adolescents at risk for anti-social behavior (Bartol & Bartol, 2011).
Dysfunctions in the brain relating to growth, chemical imbalance and injuries prevent the ability to address issues, exhibit proper emotions and solving problems inhibit behavior acceptable in society. The brain controls the entire body and mental capacity to make proper, logical, and informed choices when dealing with risk factors influencing criminal behavior.

References
Allen, C. & Harper, V. (2010). Laboratory Manual for Anatomy and Physiology, Fourth Edition / Edition 4 Wiley, John & Sons, Incorporated Hoboken, NJ ISBN-13: 9781118135662
Crime Times, (2007) A lesson from history... Phineas Gage and frontal lobe damage. Retrieved from http://www.crimetimes.org/98d/w98dp5.htm
Phillips, J. (2012). The Brain and Crime: What is the relationship here? Retrieved from http://drjezphillips.wordpress.com/2012/04/27/the-brain-and-crime-what-is-the-relationship-here/
Raine, A. (2002). The biological basis of crime. In J.Q Wilson & J. Petrsilia (Eds.) Crime: Public policies for crime control. Oakland: ICS Press