Wednesday, December 16, 2009

Are Humans Naturally Violent

Eliyahu N. Kassorla
Debate Position Paper

Are Humans Naturally Violent?
It is my firm belief that humans are naturally violent creatures. That is to say that violence is programmed deep in our biological and psychological makeup, forged by time and evolution. Those who say that humans are not naturally violent attribute the expression of violence to be caused by social learning and conditioning.
The biology of violence is four-fold: neurological, biopsychological (chemical), genetic, and evolutionary. The neurological basis for violence is seated in the emotional center of the brain, the limbic system. The limbic system, known as the paleomammalian complex in MacLean’s triune brain model, exhibits activation that corresponds to emotional expression, especially in the amygdala. The prefrontal cortex appears to act as an inhibitor to the paleomammalian complex, providing a buffer between instantaneous emotion and behavior. Violence, then, is expressed when a situation or specific stimulus overwhelms the prefrontal cortex.
Biopsychologically, aggression, the emotional precursor to violent behaviors, appears to be mediated by biochemical signals, the neurotransmitters. Certain neurotransmitters, testosterone in particular, are highly implicated in increased aggressive responses. The use of non-endogenous testosterone use causes aggressive mood and violent outbursts, colloquially known as “roid-rage.” The effects of non-endogenous sources of steroid hormones teaches us about the role the steroid plays normally, such as why higher testosterone serum levels occurs in subjects after viewing sexually explicit or violent imagery compared to pre-exposure levels. Heightened levels of certain neurotransmitters lead to an increased expression of the behavior; higher levels of testosterone cause an increased aggressive response, which in turn increases the amount of testosterone produced. This is known as a facultative trait. A facultative trait (Figure 1) is a trait, physical or psychological, that, within limits, responds, with either increase or decrease, in response to the environment or environmental stimuli.
The genetic component, shaped by evolution, determines the individual start point on the facultative response curve, and where the individual lies on the normal distribution curve for the trait (see Figure 2). If the environment necessitates higher aggression, then those with already higher aggression will have greater survivability. This concept is inextricably linked to evolution, where a trait, if considered better adaptive, will show up in individuals with higher levels of that trait and with greater frequency (Figure 3). The reverse is also true: a trait that is poorly adaptive or poorly contributes to survivability will diminish in frequency and intensity (Figure 3).
Evolution does not act arbitrarily. Violent actions can be explained by examining violence’s help in the ability to acquire resources, mating opportunities, and social status. Antlered animals are routinely seen fighting over a doe, walruses fight to the death over mating rights, and young male lions will fight a higher status lion for a higher social position. This interspecies occurrence suggests common ancestry of the trait, stemming from a common mammalian ancestor and similar biological systems. Further, in the era of evolutionary adaptation, the greatest threats to a hominid were big cats and other hominids. In this light, violence in humans serves as a protective mechanism for defense from attacks.
Learning models fail to account for the occurrence of violence without resorting to a reductio-ad-absurdum or why it works. It also ignores all biopsychological evidence with regards to the fact that neurotransmitters and key brain regions are the driving forces that determine behaviors. A key argument is the Bandura, Ross, and Ross study, which I believe to be grossly misinterpreted. In the study, children were placed in a room and made to observe aggressive play with a novel stimulus, a clown doll, then the amount of imitative behaviors were recorded. Although males scored higher across all dimensions, male children in the control group also expressed aggressive behaviors, despite there being no exposure or priming. Male children that viewed the clown doll being assaulted were significantly more likely to portray similar acts when given free-play in a room with a similar doll. Supposedly, the children learned to act violently on the doll. I suggest that there is much more going on than simple “monkey-see, monkey-do.” Firstly, there seems to be a facultative mechanism which gauges the amount of violence in the environment which primes behavior to match. Our eyeballs and visual processing pathways evolved long before we had television, meaning that if we were close enough to violence to see it with our eyes, it was probably directed at us.- and we had better be ready to respond for self-preservation. Secondly, children adaptively learn from parents and those around them who enemies and friends are. An evolutionary explanation is that if the parent has survived to produce offspring, then they are probably reliable indicators of who and what is dangerous; a similar facultative mechanism for disgust is already established in the field of evolutionary psychology – the feeling of disgust does not only come from experiencing disgust, but also seeing someone else express that feeling. Since no one came to the aid of the clown during initial exposure, a possible heuristic is that it is harmful or dangerous. For all anyone knew, attacking it was a way to make it less dangerous – it is still safer to attack first. Thirdly, other studies regarding exposure to violence and aggression have shown that as few as three days later violent outbursts and levels of aggression return to pre-exposure levels, suggesting highly that the facultative mechanism is the cause of post-exposure heightened aggression levels. scenario. Underpinning the social learning theory is the belief that human behaviors are malleable; that our behavior is the result of seeing a behavior and having that behavior reinforced with either reward or punishment. The idea that we see a behavior that works and therefore we use it, fails to account for where the very first occurrence was observed
Another case that those who advocate for social learning is that of violent video games. The failure to explain why ALL children who play violent video games to act out their violent imagery is a failing of the “observe-emulate” basis of social learning theories. A more parsimonious explanation is that children with already higher levels of aggression tend to seek out violent imagery, which increases the amount of the excitatory neurotransmitters involved in aggression and violence, leading to a corresponding increase in the expression of aggressive and violent behaviors.
Conditioning, according to social learning theory, is the ultimate source of all exhibited behaviors. I disagree for several reasons. There is a known lack of efficacy for the use of punishment and its effect on long term behavior modification. Further the Pavlovian stimulus-response relation is overly simplistic, and, according to Pavlov, should not be applied to humans. It was only by the elaborate cover-up of all research contrary to behaviorism orchestrated by B.F. Skinner in his role of president of the American Psychological Association that this model proliferated. Neurotransmitters, when activating regions of the brain, have the ability to signal a positive survival advantage, leading the paleomammalian complex to seek more activation stimuli, which in turn feeds the expression of behaviors which increase neurotransmitter relase. Conversely, by allowing neurotransmitter levels to subside to pre-activation levels, the behaviors are reduced in their expression. Heuristical models better explain paired stimuli; according to the Gestalt rule for perceptual organization (Law of Synchronicity), stimuli that appear together in time, are perceived to be linked. In nature, if an event is preceded by another event repeatedly, it is safe to assume that it may be relational. Cognition, with regards to neutral stimuli are discarded as not being relational when determining relatedness. Stimuli in nature are not arbitrary, as is the case with a loud noise when paired with food, but are perceived as environmental cues that allow us to build cognitive models and predict events.
Violence cannot be explained by learning without resorting to specious reasoning: we see it, therefore we do it; we do it because we have seen it. Instinct, not learning allows us the means to break free of the circular argument, leading to the conclusion that has served an adaptive purpose. Instinct is the protective mechanism that serves us in how to respond to novel stimuli. The behavior is “seen” because it is expressed as a result of the interaction between biopsychology and environment. The behavior is not learned, but already existed. Exposure can only elicit a response that is already present.
While there is a component of “aggression begetting aggression” and “violence breeding more violence,” it is not likely that social learning or conditioning is the mechanism of operation. Use-dependent activation and pathway sensitization are the more likely mechanisms involved. Use-dependent activation means that the degree of activation of a cognitive pathway and its synapses are facultatively dependent on use. Violence breeds violence because the “violent” pathway is already primed for use. Pathway sensitization is a phenomenon in which the more a pathway is utilized, the activation threshold for that pathway is decreased. The use of violence can create a condition where violence is elicited in future situations with decreasingly intense stimuli.
As is obvious, humans are naturally violent because of a complex interaction between genes: which code for the brain regions, structure, neurotransmitter production, and response to neurotransmitters; and the environment, for which our genes have programmed us to respond to. Evolutionary psychology provides a key perspective in understanding psychological and behavioral responses, such as the use of violence and its observation in most mammals. Cognitive psychology lends explanations to the specific pathways involved, as well as specific mechanisms for the operation of these mechanisms. Neuropsychology explains exactly what and where in the brain, and even which specific chemicals, the expression of behaviors is caused by. Social learning models do not explain mechanisms, only describe phenomenon, falls prey to the nominative fallacy, and ignores established scientific fact of the reality of biologically driven behaviors.

Bandura, A., Ross, D., & Ross, S. (1961). TRANSMISSION OF AGGRESSION THROUGH IMITATION OF AGGRESSIVE MODELS. Journal of Abnormal & Social Psychology, 62(11), 575-582.
Gaulin, Steven J. C. and Donald H. McBurney. (2003). Evolutionary Psychology, second edition. Upper Saddle River, NJ: Prentice Hall.
Goldstein, E. Bruce (2004). Cognitive Psychology. Wadsworth Publishing
Meiser-Stedman, R. (2002). Towards a cognitive-behavioral model of ptsd in children and adolescents. Clinical Child and Family Psychology Review, 5(4), 217-230


Figure 1. A facultative trait is a trait that is free to vary within limits, based on need from the environment and environmental stimuli. The sun-tanning response in humans is a facultative trait, with melanin production responding to increased exposure to UVa and UVb.

Figure 2. Traits are usually normally distributed.
(This is the only image not created by me. This image is from

Figure 3. A trait, if considered better adaptive, will show up in individuals with higher levels of that trait and with greater frequency.

1 comment:

  1. Interesting comment. This was a refutation of social learning theory, which states that literally all behavior is, essentially, mimicry. As if there is no mechanism to modulate aggression in order to respond to threats in the environment. Don't also commit the naturalistic fallacy - that I am condoning it. The bigger question is, if seeing violent news and playing violent games causes child-violence, where are the far more people who have played or seen violent things who do not commit violent or aggressive acts?

    Having the mechanisms and structures in place for aggression begs the question, if "x" is for action, what are the structures for. There are enormous negative effects to using these systems - increased cortisol, depressed immune systems, and decreased memory. Inhibiting all of these systems is the frontal lobe, and more specifically the prefrontal cortex. The mechanism exists, but the amount of input to get an output that is disproportionate to the input is the focus.

    Regarding the "eating out kids" comment, that can be explained with the altruism equation rb>c, or that the relatedness benefit is less than the cost - but we WANT to pass on our genes. That's reason when a new set of man lions come into a pride, they first kill all of the cubs. It further makes the female lions pretty immediately fertile to create cubs with the man lion's own genes.

    If this is important to you, I suggest wading through journals - that will give you a wide overview of different researchers perspectives and research focus. It is also a great way to sharpen your critical thinking skills - which you clearly display in how you've carefully brought up some points. I suggest looking at the effects of aggression on stress in non-human primates. In non-human primates, stress can cause cardiovascular disease.

    If you like video's, I suggest National Geographic: Stress: Portrait of a Killer, available on Netflix.

    Be well! Sorry about the delay!