Introduction
In 2017, 90% of the 1,873 domestic violence programs in the United States contributed to a survey conducted by the National Network to End Domestic Violence (NNEDV). In this particular survey, NNEDV collected data over a 24-hour period from the participating organizations on September 17th of that year, compiling together the number and types of calls they received. The study found that over 72,000 victims in the United States were served in a single day (NNEDV, 2017). Coupled with this information is the fact that in a study verified by the United States Humane Society, upwards of 71% of domestic violence victims stated that their abuser lashed out at pets as well (The Humane Society, 2017). Considering that animal cruelty and domestic violence are pressing issues that are often intertwined with one another, there are a few observable links that exist between the two. Some of these links include having the low activity variant of the MAOA gene, childhood trauma, heightened levels of testosterone, and exposure to societal pressures (I.e. toxic masculinity).
In this paper, these links will be analyzed, and their likelihood as being potential indicators for physical violence and cruelty will be determined. Given the fact that so many cases of domestic violence and animal cruelty go unreported every year, this paper will also establish how these links may manifest in public spaces, and how potential signs of abuse/cruelty can be reported.
MAOA-L
The MAOA gene, colloquially referred to as the “Warrior gene”, is responsible for breaking down neurotransmitters such as dopamine and serotonin. Dopamine is responsible for motor-function and releasing “feel-good chemicals”, while serotonin plays a role in regulating mood, sleep, and emotions. In individuals that have the “low-activity” variant of the MAOA gene (MAOA-L), heightened aggression and impulsiveness have been observed (Cohen, 2018). This is due to the fact that MAOA-L does not break down dopamine and serotonin as efficiently as it should. This inefficiency results in the neurotransmitters not being broken as quickly, resulting in irregularities in dopamine and serotonin levels that lead to the previously stated symptoms. That is not to say that everyone with the low-activity variant of the MAOA gene is prone to committing acts of violence, however. In a study published by the National Center for Biotechnology Information (NCBI), it is stated that approximately 40% of the world’s population has the MAOA-L variant of the gene (Hunter, 2010).
Although possessing this variant of the gene does not necessarily indicate that one will commit an act of violence, the presence of MAOA-L increases one’s likelihood to commit a violent act. Keeping this in mind, many have turned to using behavioral genetics in recent years to explain why a spouse may lash out against their partner, or commit an act of violence against an animal. In states such as Michigan, however, domestic violence and abuse are not recognized as a sufficient defense, so the application of this type of science in a courtroom setting is minimal at this point in time.
Because MAOA-L results in irregularities in the production of serotonin and dopamine in one’s body, this leads to blind aggression. If someone with MAOA-L is provoked, they will typically lash out on what provoked them in a verbal or physical manner. This implies that this particular link between domestic violence and animal abuse is not necessarily causal, as the associated gene is largely blind to particular instances due to the fact that aggression spurred by MAOA-L is mostly impulsive.
Childhood Trauma
Another link between domestic violence and animal abuse can be observed through individuals that have suffered childhood trauma. Due to the fact that people often experience a tremendous amount of neurological development during their adolescence, particularly traumatic events may lead to inhibited growth of the prefrontal cortex, which is responsible for “executive functions” that control impulsiveness, rationale, and aggression (Prefrontal Cortex, 2015).
For children that have experienced childhood trauma that also codes for the low activity variant of the MAOA gene, their likelihood to commit an act of domestic violence or abuse animals raises even more. If one’s amygdala and prefrontal cortex are stunted/damaged, this has been shown to interfere with one’s ability to make rational decisions and reign in their emotions. With an inadequate dispersal and production of dopamine and serotonin as a result of MAOA-L, this would intensify one’s emotional instability.
A study published by NCBI pointed to a lack of nurture on behalf of parents may also lead to developmental disorders down the line such as Oppositional Defiant Disorder and Conduct Disorder (Petersen, 2014). Oppositional Defiant Disorder is the tendency to defy authority figures. This could include police, teachers, and parents. Conduct Disorder, on the other hand, is often categorized as a disorder wherein someone will not abide by conventional social norms, and instead express regressive behavioral patterns. What is peculiar about these two disorders is the fact that they are both diagnosed during adolescence, and presumably influenced by genetic and environmental factors. In analyzing CD and ODD, antisocial and disobedient tendencies have been observed at much higher rates in criminals that have committed physically violent acts such as murder, rape, and domestic abuse. (Febres, 2014)
Perhaps the most prominent link between animal abuse and domestic violence as it pertains to childhood trauma has been through the act of committing animal abuse during one’s adolescence. In studies with criminals that have been found to have caused unnecessary pain and/or death to animals while they were children, it was found that they were more likely to carry those acts of violence into adulthood. It was also found that many offenders would commit acts against people that were similar to acts they committed against animals. This points to the fact that animal abuse may in some ways “condition” offenders to commit violence against their spouse, or other individuals that may set them off (Febres, 2014).
Hormonal Aspects of Violence
Testosterone is the sex hormone found in males that is responsible for developing secondary sex characteristics (body hair, muscle growth) and the male reproductive system (scrotum, prostate, testes, etc.). While development is testosterone’s primary function, there are some additional effects, particularly as it pertains to mood. Testosterone is an anabolic steroid. Like other identified anabolic steroids, testosterone leads to increased activity in the amygdala, which is responsible for emotionally driven responses and actions. Because there is increased activity in the amygdala, this redirects most neural communication away from the prefrontal cortex, which is responsible for rational decision making, leading to heightened levels of aggression and a shorter temper (Pinto, 2010).
In a study researching the “biological correlates of intimate partner violence perpetration”, it was corroborated that testosterone does, in fact, lead to heightened levels of marital aggression, as well as an increased risk in committing intimate partner violence. While it has been found that testosterone does indeed result in heightened levels of aggression, it has also been found that it may be mediating as it pertains to the quality of one’s marriage. Despite this conflicting finding, it has also been found that people are more likely to file for divorce as well (Pinto, 2010).
Much like the previously established links, the correlation between animal abuse and domestic violence is aggregated through aggression and rage. In a study published by American Humane, it was stated that 71% of women seeking shelter from an abusive partner stated that their partner threatened to kill, harm, or maim their pets. As this study looking into domestic partnerships between men and women, a likely inference can be drawn that these abusive partners in fact had heightened levels of testosterone, given their overtly aggressive tendencies (Understanding the Link Between Animal Abuse and Family Violence, 2016)
Societal Aspects of Violence, and Toxic Masculinity
So far, three links have been established between animal abuse and domestic violence that have largely been based on behavioral genetics. One additional link between these two acts can be drawn not through genetics, but environmental factors. The most prominent among these is the idea of toxic masculinity, and the cycle of socialization.
The principal idea of the cycle of socialization is that from birth, one is socialized by their environment, and bombarded with messages that reinforce particular ideologies. This includes gender norms, religious beliefs, and specific behavioral patterns. This pattern of socialization in the most extreme of circumstances may lead to someone’s upbringing having a negative effect on their temperament and reactions to certain individuals.
Toxic masculinity, referred to as hegemonic masculinity in the field of gender studies, is one trait that may be acquired through socialization. The core tenet of hegemonic masculinity is Manifestation of Links in Public Spaces.
Conclusion
At the root of all of the links between animal abuse and domestic violence that have been observed in this paper lies aggression, neurological anomalies, and errors associated with cell communication and/or signaling. All of these signs and symptoms, while not 100% indicative of the likelihood of one to commit an act of violence or animal cruelty, do in fact point to an increased likelihood of doing so. From the data compiled above, the most likely offenders are going to be males with high levels of testosterone that have the low activity variant of MAOA, who have also experienced stunted growth of their prefrontal cortex as a result of childhood trauma. At the end of the day, however, anyone is capable of committing acts of violence. It is for this reason why the behavioral genetics that points to the increased likelihood of committing acts of violence should be noted, but not used as definitive evidence to apprehend or besmirch someone.
Since behavioral genetics is a relatively new field that is constantly experiencing brand new developments, the science behind why people commit acts of domestic violence and animal abuse is not entirely clear. While researchers have published papers on apparent links between the two, as well as reasons why people may commit overt acts of aggression during their adolescence and adulthood, all of the factors associated with it have not been properly identified. This can be observed through the fact that not all perpetrators of domestic violence and animal abuse are men with MAOA-L, heightened levels of testosterone, and victims of childhood trauma. This indicates one of two things: There is a common factor that has not yet been identified or each of the identified factors that boost the likelihood of committing a violent act are not necessarily intertwined. Because of the current ambiguity surrounding the topics of domestic violence and animal abuse and their linkage as it pertains to behavioral genetics and environmental factors, research of this topic is far from conclusive.
