Cause of Deviant/Criminal Behavior and Stimuli Specific to Sexually Deviant Behavior Towards Adults and Children

 Photo by Louisa Gouliamaki/AFP

Photo by Louisa Gouliamaki/AFP

By Tommy L. Smith

Senior Criminal Intelligence Analyst, Leon Sheriff's Department

Graduate Student at American Military University

NOTE: This scholarly article was written as a research project for AMU's CMRJ515 - Sexual Exploitation of Children graduate course. This article has been edited for this site. 

Biological Theories 


        Hundreds, perhaps thousands of studies have been completed to examine the root causes of deviant behavior. Some biological theories, most of which have strong scientific backing, have surmised that genetics, hormones, brain chemistry/structure, and anatomy can affect a person’s mindset enough to spark said deviant behavior (Rivendell, 2016). One theory regarding genetics and deviant behavior infers that the genetic makeup of males causes them to commit crimes. Statistically, more males than females are arrested when it comes to deviant and criminal behaviors; however, such theory has been all but discredited (Howit, 2009). Another interesting genetics theory speculates identical twins are more likely to share criminal tendencies than other individuals and non-identical twins, suggesting that the environment and upbringing would not factor into the twin’s deviant behavior (Viding et al, 2005).

Brain Chemistry

        Biological theories of criminal behavior are not limited to gender and sibling relationships. In fact, brain chemistry is thought to play a large role in forming criminal behavior. There are several chemicals within the brain that affect different moods. One of those chemicals is specific to the neurotransmitter called serotonin. Another chemical mostly, associated with males is testosterone. Testosterone is a hormone, which when it is at high levels, causes aggression (Rivendell, 2016). Interestingly, the vitamin Omega 3 has been linked to lowering aggression, while poor nutrition is linked to higher levels of aggression (2016). 

Brain Structure & Anatomy

        It is a common notion that the human brain is made up of many parts (the larger of them called lobes) that are responsible for different bodily functions. The amygdala, for instance, are two spherical-shaped masses within the temporal lobes of the human brain. This part of the brain is responsible for emotions, and the belief is that damage to this area can be associated with causing criminal behavior because the person may no longer feel fear or have empathy toward other people (Rivendell, 2016; Raine, 2008). Other theories relating brain structure to criminal behavior involves the part of the brain that stores memories – the hippocampus. It is speculated that damage to the hippocampus could remove any residual memories of being punished for a criminal act, and given the extent of the amnesia, short-term or long-term memories could be repeatedly affected (2016). Additionally, the frontal cortex is associated with self-control, so if that were damaged, it could remove inhibitions (2016).

Biological Theory - Case Study

        Phineas Gage was a normal, mild-mannered and hard-working railroad foreman in Vermont in the mid-1800s. He was planting explosives as part of his job and a spark ignited one of the explosives prematurely. The tamping iron he was using to pack sand over the explosives was sent upward, where it made entry through his left cheek and exited out of his frontal cortex, landing several feet behind where he was standing. While Phineas did survive and seemingly made a full recovery, people who knew him best stated he was no longer the “same person” and was no longer mild-mannered or conscientious. In fact, he became verbally aggressive and unreliable at work, so the railroad company had to terminate his employment. 

Social/Personality Theories 

Social Learning Theories 

        Children are impressionable and much of what they see growing up can influence their behaviors in the future. Psychologists and criminologists have theorized that classical conditioning, operant conditioning, and observational learning can all affect the ultimate behavior of a child as the child grows. Classical conditioning was made famous by a Russian physiologist named Ivan Pavlov, wherein he trained dogs to salivate at the sound of a bell (Rivendell, 2016). In humans, certain stimuli or “triggers” can instill specific responses (i.e. children who are raised to hate those of a certain race – when they see a person of that race, the hate resurfaces. The child may be taught to react in a certain manner). With operant conditioning, an association is made between a behavior and a given consequence for that behavior (Bartol & Bartol, 2011). For instance, if something works the first time, it may be successful again. In a criminal setting, an abusive husband who knows he can get away with hitting his wife because she is afraid to tell anyone, may continue doing so because it worked the first time. The last social learning theory, observational learning, refers to any tendencies or habits learned as a result of watching someone else (i.e. “monkey see, monkey do”) (2016).

Routine Activity Theory

        This theory ties directly in with some of the aforementioned learning theories. After a person learns how far they can push the limits and get away with it, they repeat the process continuously since it is effective. Three (3) elements that must be present according to this theory are: motivation, a suitable target, and absence of guardians or authoritative bodies (Clarke & Felson, 1993).

Strain Theory

       In the criminal justice field, there is arguably no theory better known as the strain theory (with exception to the Broken Windows Theory). Not only in America, but in other parts of the world, there are impoverished nations. Sometimes, children and adults feel as if they have no way to attain the things they desire (i.e. a better lifestyle, new car, nice house, new clothes, etc.). In some cases, these people who feel “strained” find a way to achieve what they want – by engaging in illegal activities and taking from those whom they feel have a better lifestyle (Agnew, 1993).

Control Theory

        The last psychological theory discussed is known as the Control or “Marxist” Theory. It is the thought that transitioning from capitalism to socialism and is part of the inevitable societal evolution. Additionally, it is seen as being developed solely by dominant social classes for the benefit of dominant social classes, which in turn, causes resentment from middle and lower classes and eventually, rebellion (Bonger, 1916).

Possible Causes of Deviant/Criminal Victimization of Children

NOTE: The information contained within the next two paragraphs is based on responses from state prisoners. 

        In a report completed by the Bureau of Justice Statistics, research found that most of the prison inmates convicted of sexual assault and/or molestation of a child, victimized children that were personally known to them, as opposed to randomly selected strangers (Greenfeld, 1996). Of those inmates, nearly 33 percent victimized their own child or their stepchild (1996). Perhaps, the most interesting detail, which separates general offenders from offenders who commit crimes against children is that most offenders were abused (often sexually) at some point during their childhood (1996).

        Statistically, approximately 97 percent of offenders who committed violent crimes against children at the time the Bureau of Justice Statistics created its report were male. Further, nearly 70 percent of those males were Caucasian. The report also found that most offenders convicted of crimes against children were less likely to have a prior criminal record than general violent offenders (Greenfeld, 1996).

What is a pedophile and what is it that makes people sexually victimize children?

        There are many categories of sexual offenders. Perhaps, the most commonly used term is “pedophile;” however, that term describes the psychological state of the person, not the criminal act they may carry-out. The American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders formally defines a pedophile as a person who possesses sexually arousing fantasies, impulsive desires, or behaviors about or involving sexual acts with children, occurring over a period of at least six (6) months (Cochran & Cole, 2010). While those who suffer from this mental disorder do have a compulsion to sexually abuse young children, it does not always mean they will act on it.

Causes of Pedophilia

        Just like with general criminal offenders, pedophilia can be attributed to some biological and environmental factors, including cerebral dysfunction. This could affect self-control and cause cognitive distortions (Scott et al, 1984). For instance, a person suffering from this disorder may not be able to suppress their urges to have sexual relations with children. Furthermore, early neurodevelopmental perturbations can cause the abnormalities in the human brain (Schiffer, 2008). Pedophiles specifically exhibit abnormalities in the central and front regions of the brain and have decreased brain matter, thereby affecting the nucleus accumbens (extended amygdala), frontal cortex, and cerebellum (2008). These areas of the brain, working in cohort, complete the “reward system” of the human brain. In other words, if this system is not working correctly, typical sexual activity between adults may not be enough to appease a person, ending with them having pedophilic tendencies (Cochran & Cole, 2010).

        Further analysis into the brain functions of pedophiles revealed frontotemporal dysfunctions caused mental disorders to be similar to obsessive-compulsive disorders; therefore, pedophiles may act inappropriately and maintain poor self-control while repeating the same actions repeatedly and concentrating on perfection. Because the neurological dysfunctions mentioned above relate to self-control and not emotions, a true pedophile often feels guilty or shameful after partaking in an immoral, socially unacceptable, and/or illegal action with a child (Schiffer et al, 2007).

Applying General Offender Biological and Psychological Theories to Sex Offenders

         In a dissertation completed analyzing comparisons between the general Strain Theory and juvenile sex offenders, there were no significant differences between general violent offenders and sexual offenders related to negative life events, academic failures, lack of self-esteem, depression, problems with drugs, etc. (Colbert, 2004, p. 51). The doctoral candidate hypothesized that something as simple as a student who qualifies for reduced cost or free lunches had an effect on juveniles becoming sex offenders. He theorized that this could be related because families that have greater financial stability keep their children out of the juvenile justice system, by seeking expensive counseling or therapy (2004, p. 51). As suggested by previously cited sources in this research paper, maltreatment is a significant indicator that a person may become a violent criminal or sex offender. The doctoral candidate found that the majority of the sex offenders studied had parents or legal guardians that were previously investigated by an agency of child services, where a child (sibling) may have been removed from the home due to allegations of abuse or sexual assault on a child (2004, p. 52).

        In a research brief published by the Office of Justice Programs’ Office of Sex Offender Sentencing, Monitoring, Apprehending, Registering, and Tracking, social learning theories were found to be related to sexual offending behavior. This brief suggests that pornography serves as a model for sexually aggressive behavior for some individuals, which encourages them to engage in similarly aggressive behavior in everyday life (Faupel, 2015). Not surprisingly, this brief concurs with other studies cited previously regarding biological theories as they relate to sexual offenders. The brief explains that several studies found abnormalities in the brains of some sexual offenders examined, while other studies showed some linkage between hormonal abnormalities (i.e. testosterone levels). Furthermore, studies have examined the possibility of the presence of genetic defects in sexual offenders, which may be responsible for the likelihood they engage in illegal sexual activity (2015). The brief also concluded that personality disorder theories are sound, in that sexual offenders (as a majority) possess poor social skills and have issues with intimacy. The brief further explains that due to a lack of empirical evidence, personality traits alone do not account for the cause of the sexual offending behavior (Faupel, 2015).

Release and Recidivism

         There are many factors that affect whether a prisoner is released, regardless of whether he/she is a general violent offender or an offender who has sexually victimized as an adolescent. According to a study published in the Journal of Criminal Justice, there are three (3) categories of “strain” that stimulate negative emotions and can lead to crime of delinquency: the loss of positive stimuli, inability to achieve one’s goals, and the imposition of negative stimuli (Ackerman & Sacks, 2012). This statement concurs with previous sources in that the strain theory can have influence in one becoming a sexual offender. If the studies are correct and the strain theory is applicable to sexual offenders (including those who target and victimize children), then it can be inferred because a person is surrounded by negative stimuli, lacks positive stimuli, or feels as if they cannot achieve their goals, they will commit initial crimes and repeat crimes (even after release from incarceration) due to the imposition of negative emotions.

Problems with the Current Correctional/Rehabilitation System

        No rehabilitation, penal, or correctional system is perfect, as they are man-made and man is not perfect. In fact, some processes practiced in certain systems could potentially be detrimental to the psyche of an offender and contribute to their “strain.” For instance, many criminologists view the mandatory registration and community notification of sex offender identities and locations as a source of stress or strain on the offenders (Ackerman & Sacks, 2012). Due to this, it is widely speculated that this particular system has the effect of increasing occurrences of reoffending, which was supported in the study published by Ackerman and Sacks (2012).

Conjecture Surrounding Contributing Factors & Etiology

        In addition to popular theories discussing biological causes (brain chemistry, brain structure, and genetics) and those discussing social causes (strain, routine activity, and control) of deviant behavior and sexual-specific deviant behavior, there are multiple avenues that have been touched upon and explored, but perhaps not thoroughly enough. A few studies have been completed on hormone levels of sexual offenders, particularly testosterone in male sexual offenders (testosterone was briefly mentioned in the “Brain Chemistry” section of this paper, but I discussed in more detail here). One study published in Sage Journals, examined over 500 adult male sexual offenders who were enrolled in a psychotherapy program. In that study, the majority of the men who committed the most violent sexual crimes had significantly higher levels of testosterone, as opposed to men who committed less-violent sexual crimes (Studer, Aylwin, & Reddon, 2005). Additionally, the study found that testosterone in men was successfully predictive in determining whether or not they would reoffend – useful in estimating recidivism rates (2005). For reference, testosterone is known as the male hormone, aggression hormone, and the masculinity hormone.

        In an article published by The British Psychological Society, several studies were examined and the Society found that violent actions and testosterone are related via threshold, meaning that after the hormone has reached high enough levels, it can lead to negative behavioral changes in certain circumstances (Neave & O’Connor, 2009). Additionally, the article found that testosterone plays a significant role in governing sexual behavior in humans, especially males, and when the levels are too low, sexual functioning is impaired; however, when the levels are high, sexual function is at its peak (2009). Further, the article found evidence that indicates sex hormones (such as testosterone) particularly affect cognitive functioning in brain structures (2009), meaning that if testosterone levels are significantly lower or higher than normal, emotions and decision-making ability can be compromised.

        Another theory is directly related to certain psychological and brain chemistry theories presented in the preceding sections – that is the theory circling a psychological condition known as sexual addiction. While there are no definitive causes for this disorder, an article published in the Edgmont Psychiatry Journal emphasized that hypersexual behaviors that stem from sex addiction have been confirmed in patients and offenders with tumors, frontal lobe lesions, seizures, Huntington’s Disease, dementia, and other conditions that affect the midbrain or temporal lobes (Fong, 2006).


Restatement of facts, answered questions, final analysis (with hypothetical example)

        This research project examined contributing factors that can aid in the development of deviant/criminal behavior. Additionally, research was conducted on the understanding of pedophilia, the categories of pedophilia, and what may cause it. After an exhaustive review of empirical data and presentation of psychologically-and-scientifically-proven concepts, other potential etiologies were explored. After extensive research, the questions are posed here again:

What is it that causes people to become criminals?

        People become criminals for various reasons. As presented in this paper, biological factors such as genetics, brain chemistry, and brain structure and anatomy can and influence deviant behavior; a case study was provided showing historical evidence of this. Certain social situations influence deviant behavior as well, including what is seen and heard in a childhood home and in a neighborhood growing up, as well as strain and stress in a subject’s life.

Why do some of these criminals victimize children?

        One of the root causes is a psychological condition known as pedophilia. Alone, pedophilia is not a crime. It only becomes illegal when the subject succumbs to his or her urges and sexual fantasies toward children, whether that is by viewing or taking pornographic photos of children or engaging in physical sexual activity with them. Review of additional data suggests that the Strain Theory and other biological traits come into play, whereas children experience negative life events, academic failures, lack of self-esteem, depression, and problems with drugs growing up; it could be that, combined with anatomical depravities in the structure or chemical composition in the brain which causes an offender to sexually abuse children. Additionally, hormonal imbalances, abuse as a child, and any sexual addiction condition can influence violent and sexual behavior toward children.

What causes some sex offenders to reoffend and why is the current correctional system not effective in dissuading future criminal acts?

        Based on research presented, sex offenders and offenders in general all have unique personality and biological traits, so no system can be perfectly adjusted to meet conditions appropriate to all offenders. Other information uncovered during research suggests that, in prison, if a person is surrounded by negative stimuli, lacks positive stimuli, or feels as if they cannot achieve their goals, they will commit initial crimes and repeat crimes (even after release from incarceration) due to the imposition of negative emotions. Further, and perhaps even more dumbfounding, is the conclusion that despite the benefits mandatory sex offender registration provides to law enforcement and the general population, it can negatively affect offenders due to imposing additional stress or strain (mainly from embarrassment or anger).

        Final Analysis and Conclusion: People become criminals due to one or many contributing factors, including psychological, environmental, and chemical stimuli. Of those criminals, some may experience specific types of trauma at a young age which alters their state of mind, prompting them to sexually abuse children. Another notion, based on analysis presented within this research, is that when a child is sexually abused, not only is long-lasting psychological damage probable, but also a change in hormonal balances and how that child may view people of the same and opposite gender going forward. As a hypothetical example:

        John was five (5) years old when his father sexually abused him – multiple times. While growing up, John had a high level of testosterone and was very aggressive in high school. Just a few years after graduation, John was convicted of molesting another young boy. Based on this story and on empirical findings from research presented, John’s high level of testosterone coupled with the mental impact the sexual abuse by his father had, it is likely when he was getting older he had homosexual tendencies but also a need to be dominant. On the other hand, if a small girl is sexually abused by her father, she may lean more toward the same sex or, if a certain number of chemical and psychological stimuli are present, she may seek affection from the opposite sex but could still have residual fear.

        Quite simply, the reasons for deviant behavior and child-specific sexually deviant behavior are vast in number. The reasons an offender reoffends are nearly as expansive. Sexually deviant behavior toward children is an unfortunate phenomenon that must be researched further. While the criminal justice system does prosecute and monitor known offenders, more analysis of the psychological causes and potential treatments for criminal pedophiles and general sexual offenders is needed. Perhaps one of the most unnerving truths about sexual crimes against children, in particular, is that it is a transcendental category of crime – in other words, it causes a chain reaction (when one child is abused, there is the high probability that child may repeat the action to another). 


Ackerman, A. and Sacks, M. (2012). Can General Strain Theory Be Used to Explain Recidivism Among Registered Sex Offenders? Journal of Criminal Justice, 40(3), 187-93. Retrieved from

Agnew, R. (1993). Why do they do it? An examination of the intervening mechanisms between “social control” variables and delinquency. Journal of Research in Crime & Delinquency, 30(3), 245-266.

Bonger, W. (1916). Crime and Economic Conditions. Boston,MA: Little Brown.

Clarke, R. V. and Felson, M. (1993). Routine activity and rational choice. Piscataway, NJ: Transaction Publishers.

Cochran, M. and Cole, M. (2010). Inside the Mind of a Pedophile. Retrieved from

Colbert, S. (2004). Applying General Strain Theory to Juvenile Sex Offenders (Doctoral dissertation). Retrieved from ProQuest (#3143540).

Faupel, S. (2015). Etiology of Adult Sexual Offending. Office of Sex Offender Sentencing, Monitoring, Apprehending, Registering, and Tracking. Retrieved from

Fong, T. (2006). Understanding and Managing Compulsive Sexual Behaviors. Journal of Psychiatry – Edgmont, 3(11), 51-58. Retrieved from

Greenfeld, L. (1996). Child Victimizers: Violent Offenders and their Victims. U.S. Department of Justice & Bureau of Justice Statistics. Retrieved from

Howit, D. (2009). Introduction to forensic and criminal psychology (3rd ed). Harlow, UK: Pearson Education.

Neave, N. and O’Connor, D. (2009). Testosterone and male behaviors. The British Psychological Society, 22, 28-31. Retrieved from

Raine, A. (2008). From Genes to Brain to Antisocial Behavior. Current Directions in Psychological Science, 17(5), 323-328.

Rivendell, Anne. (2016). Psychology of Crime: Why Do People Become Criminals. Retrieved from

Schiffer, et al. (2007). Structural brain abnormalities in the frontostriatal system and cerebellum in pedophilia. Journal of Psychiatric Research, 41(9), 753-62. Retrieved from

Schiffer, et al. (2008). Brain response to visual sexual stimuli in homosexual pedophiles. Journal of Psychiatry and Neuroscience, 33(1), 23-33. Retrieved from

Scott M. et al. (1984) Neuropsychological performance of sexual assaults and pedophiles. Journal of Forensic Science, 29(4), 1114-8. Retrieved from

Studer, L., Aylwin, A. and Reddon, J. (2005). Testosterone, sexual offense recidivism, and treatment effect among adult male sex offenders. Sexual Abuse: Journal of Research and Treatment, 17(2), 171-81. Retrieved from

Viding, E. et al. (2005). Evidence for substantial genetic risk for psychopathy in 7-year-olds. Journal of Psychology & Psychiatry, 46(6), 592-597.



The Author

 Tommy L. Smith

Tommy L. Smith

Tommy L. Smith is a senior criminal intelligence analyst for the Leon County Sheriff's Office in Tallahassee, Florida. He graduated from the Florida Law Enforcement Analyst Academy in 2015 and is a Certified Law Enforcement Analyst. Tommy is trained in crime analysis, Geographic Information Systems (GIS), and intelligence analysis and has received extensive training in emergency management, communications, disaster response and recovery, emergency planning, and multiagency coordination through the National Incident Management System (formerly the Incident Command System) of the Federal Emergency Management Agency.

Tommy's expertise lies within geographic profiling and analysis and has interests and research experience in several facets of the intelligence and criminal justice sectors such sexual deviant behavior and bioterrorism. He is current a graduate student with American Military University, pursuing a Masters of Homeland Security with a concentration in Criminal Justice.