Posted at 10.03.2018
Human aggression is the display of behaviors aimed at harming or destroying the target. The study of aggression and its own causes is a sophisticated one as it indicates a broad array of triggers, triggers, stressors and connections among them and requires an interdisciplinary strategy. In inspecting the biological factors behind aggression there has been in the past diffidence because of the risk that its simple notion may imply determinism, thus restricting the flexibility of the human being. Nonetheless the study has confirmed that biology affects behavior and this genetics correlates with aggression.
After reviewing this is of aggression, I will review the natural causes (dynamics) and the cultural/relational triggers (nurture) and I'll attempt to clarify if currently the research has come to a answer on what factors determine aggressive behavior.
Definition and explanation of aggression
Aggression in humans is a hostile or harmful action. It comprehends all manners targeted at attacking someone either verbally or actually, with the purpose to harm the mark.
If we go through the animal world, we see that hostility not only is present in all kinds, but actually it offers an evolutionary advantages: it helps to protect the individual, or at least the continuity of the specie. Family pets differ included in this in the habits of behaviors exhibited in an assault. Often the hostility is limited to a hazard, leading to set up a hierarchy in the pet group, without harming the other individual (Carlson, 2010). This rules of the aggressive behavior (from genuine attack to risk) seems to be an evolutionary good thing about the specie, as it inhibits the physical elimination of customers of the group. Studies of the neurophysiology of pets show that when aggression is directed towards members of the same varieties, the aggressive individual displays a high degree of arousal and activity of the sympathetic anxious system. This does not happen when an pet is involved in attacking an associate of different varieties to provide food for home or users of its group. We can say that in this predatory activity, there is no feeling like anger to the prey, but instead a very "cold" pursue of an objective (Carlson, 2010).
These observations in pets or animals echo the classification of aggression in humans often found in literature of hostility. Aggressive behaviors are often labeled into two categories: impulsive (or affectively evoked, or reactive) or predatory (or premeditated, or proactive, or instrumental). Some authors also make another category for the defensive hostility (Coccaro & Siever, 2002): the ambitious behavior is at response to a genuine threat and its own purpose is to deduce the danger. If this differentiation would be intuitively recognized in animals, I contemplate it misleading as it pertains to humans, as it is difficult to tell apart between real and recognized risk, as it occurs for example in a paranoid condition: what can be identified externally as an unjustified invasion, in your brain of the aggressor it is simply an action of security from a recognized danger. Therefore the difference between defensive and attacking aggression seems to be just a moral construct, efficient to the decision whether to intervene or not. In other words, if the displayed aggression is socially suitable or not. From a psychopathology perspective, hostility is not pathology alone, but rather an element of several mental disorders, as identified in the DSM IV-TR.
A massive amount literature deals with ambitious and violent habit altogether. We have to clarify that assault is not a synonym of hostility, but instead one of its manifestations: violence is an hostility carried out to physically damage or get rid of the target of the action. A large amount of research in neuro-scientific hostility has been conducted right in its extreme form of violence, as the severity of the take action in itself offers cases where the causes behind the habit are more obvious than in situations of less extreme hostility, so that they can be better discovered. In this way, studies of criminals and of their instances allowed to better describe reactive and predatory assault: reactive violence implies intense activation of the sympathetic nervous system, strong emotions and immediate a reaction to the cause, with the goal of reducing the menace that the cause of the hostility is identified to cause. Reactive violence is usually displaced quickly after a display of behaviors that announce the imminent violence. On the other hand, predatory violence is not associated with sympathetic arousal or perceived emotions and appears to be targeted at a multiplicity of goals, and lack of a perceived threat. It is usually planned in advance and accompanied by rituals, generally of symbolic meaning, performed privately (Meloy, 2006). Studies of forensic populations suggested that those who have employed in predatory violence 're normally diagnosed as psychopath with the use of the Psychopathy Checklist-Revised (PCL-R), while the top features of affective violence are among the list of diagnostic standards for antisocial and borderline personality disorders, and intermittent explosive disorder (Kokler, Nelson, Meloy & Sandford, 2006).
One additional key difference between predatory and affective assault is the fact in the former case, the perpetrator displays an increased and targeted attention, that allows him to plan and implement all the necessary actions to reach his goal. Criminals who've perpetrated violent works of affective type seem to be to possess acted on the basis of cognitive dysfunction: the exec functioning seems to be impaired and the subject's actions are mostly managed by the turned on sympathetic nervous system (Kokler, Nelson, Meloy & Sandford, 2006).
The explanation of the top features of impulsive or predatory aggression offers an extremely valuable framework to study the dynamics of hostility and its own possible treatment or avoidance. However, it generally does not clarify why a lot of people engage in types of aggression, more that other individuals. The examination of the causes therefore should be directed towards the identification of the factors which makes higher the threshold to competitive patterns. If we reason in line with the frustration-aggression model defined below, this might mean to understand and address those factors that make one individual more resilient to annoyance compared to another one who instead responds with aggression. I am going to review the complexities found in books.
Organic causes (Character)
Genetic correlation is still debated and the findings remain inconclusive. The primary debate on the study on the implications of the XYY and XXY chromosome has been focusing of the biases of the original analysis, as we were holding made on convicted population and not on the overall human population. A longitudinal research released in 1999 (G¶tz, Johnstone & Ratcliffe, 1999) detected that the bigger rate of antisocial behavior and conviction of the group with the XYY chromosome was to be attributed more to decreased brains than to increased aggression. It is also noticeable that the offences were mainly against property than against people. The finding that the group with the XXY chromosome did not show increased rate of conviction is in accordance with the 36-years long Denver Analysis (Bender, Linden, & Harmon, 2001), which found lower degree of cognitive ability, but overall good interpersonal adaptation in the XXY group set alongside the control.
Another blast of research to judge the genetic affect in aggressive tendencies is dependant on observation of twins, brothers and adoptions. Indistinguishable twins seem to be more concordant than non-identical twins for criminality, indicating that some factors resulting in criminal patterns are sent genetically (Raine, 2002). Also several studies with adoptive children show a genetic relationship with criminality, although some studies, which also analyzed the type of offence, mentioned that the increased rate of criminality in used children with legal natural parents was scheduled to petty property criminal offenses and not assault (Raine, 2002).
Physiological correlations with ambitious behavior include influence of serotonin, hormones, brain functioning, EEG and Cardiovascular underarousal.
Evidence shows that serotonin inhibits human being aggression. This information has been backed by both studies that assessed the amount of serotoninergic activity and the exhibited aggressive tendencies, as well as in studies that examined the decrease of the aggressive tendencies by using serotonin agonist drugs (Carlson, 2010).
Evidence that testosterone boosts aggression are clear, so that is one of the things to consider, but its weight in the rules of aggression continues to be not described (Raine, 2002).
A critical role in the inhibition of hostile behavior is played by the ventromedial prefrontal cortex of the brain. Like in many cases of research of brain functioning, also for the correlation between this part of the mind and aggression, strong indication is provided by situations of brain lesions: patients with a lesion of the prefrontal cortex appear to have behavioral and decision making complications, mainly due to having less regulation of emotions that are generated in the amigdala (Carlson, 2010). Practical imaging studies of the brain showed that individuals convicted for murder had a significantly poorer activity of the prefrontal cortex, compared with control group (Raine, 2002). This finding reinforces the ipothesis that the prefrontal cortex plays a major role in control and inhibition of all those actions that be based upon emotions, like hostility, problem handling, risk taking, all characteristic involved with antisocial disorder. This means that the factors that cause an impairment of the function of the area of the brain will probably have a correlation with increased aggressive behavior. This has been found true for delivery complications, especially specific complications like anoxia and forceps delivery, although not as a unique determinant, but combined with maternal attention factors (Liu, 2004).
Another part of the brain that has confirmed a significantly poorer function in murderers is the left angular gyrus: lower activity of this portion of the mind is correlated to cognitive deficiencies like terms or mathematical skills (Raine, 2002). It is likely then that its poorer activity of the still left angular gyrus in criminals is not directly related to increased hostility, but rather has resulted in more difficult living conditions through troubles in university and career, thus planning the conditions for being involved in offense.
A triad of physiological conditions has also been correlated with offense in a potential review: low heartrate at leftovers, high presence of slow waves in the EEG, and low skin conductance were -collectively- correlated to offense in the next ten years (Raine, 2002). As these physiological conditions are observed in condition of under-arousal, the writer suggests that a theory of under-arousal in hostility could be explored, as this condition has been related to fearlessness and thrill-seeking, both the different parts of anti-social patterns.
The effect on aggressive habit of the experience through which the average person goes into its life, and especially during infancy, youth and adolescence is identified in books through several models or perspectives. Each one appears to capture one or some aspects of this complex theme of how aggression is learnt, developed or manipulated and inhibited.
Social Learning theory (cognitive-behavioral point of view): identifies learning as a consequence of imitation, and observational learning. The role of imitation was verified in the series of tests that Bandura (Bandura, 1973, quoted in Liu, 2004) conducted to evaluate if children would imitate the competitive action that they just detected performed by others. Observational learning increases this simple imitation device the observation of the positive effects of the hostile tendencies (Liu, 2004), leading to a encouragement of the appropriateness of the ambitious behavior to follow own goals. This sort of observational learning has been called to spell it out the unwanted effects on children of violence in Tv set or videogames.
Frustration-Aggression Model: explains aggression as a consequence of experience stress in non-achieving a desired goal. As this theory suggests experiencing emotions like frustration and anger, it addresses affective hostility, but does not clarify the predatory aggression (Berkowitz, 1989).
Family violence and misuse are conditions where aggressive tendencies can be learned: the child imitates the replies that violent parents are usually demonstrating, while an abused child can as an adult repeat the same abuse on his or her own child, as the maltreatment cycle theory explains. However, not absolutely all children via violent or abusive family members become criminals as parents, suggesting that many components build the picture of cognitive and psychological development of people.
Aggression is intrinsic in pets or animals and in human beings and can't be eliminated. The brain structures that seem to be directly involved with its regulation participate in a more recent -from an evolutionary point of view- area of the brain, the prefrontal cortex. We can thus claim that the evolution of which the individuals is the result has considered an advantage to the specie an extremely sophisticated device of inhibition of competitive behaviors.
In reviewing the books on the mechanisms and causes of aggression a number of factors make more challenging the analysis of the comparative impact of character or nurture on intense behavior (retrospective studies on preferred populations, overlapping of definitions that make difficult the generalization of specific cases, small size of the populations in the studies). Nonetheless, an enormous amount of books suggests that hostility is inspired by biological factors and has at least some genetic components. Genetics studies still pose the question of what is actually inherited, because - although familiarity has been found - often the inherited feature appears to not be a direct result in of aggression, but instead a cognitive feature that impact the introduction of personality (like reduced intelligence in the XYY chromosome disorder). It really is noticeable therefore that the demonstration of aggressive behavior is the result of a complex collection of events that require both biological structures and environmentally friendly forces that shape the cognition and passion and that at exactly the same time are formed by these evolving functions of the child. At this regards it is worth to say the question that Raine (2002) expresses discussing the studies on adoptive children that analyzed the relationship between inherited hostility and adoptive parental health care. For some children who acquired criminal parents (probability of inheriting hostility) and were rejected by the adoptive parents, he wonders if the rejection was actually because of the behavior of the kid, somewhat that to the personality of the parents, indicating that the child himself produces environmental conditions that could aggravate the chance to incur in aggression, in a vicious group.
Whether biological or environmental factors accomplish the looks of aggression, one aspect to be considered in striving to discover a clear predictor of violent action, are the ethical implications. One example is the strong question induced in 1999 when the united kingdom Section of Health alongside the Home Office released a paper with a proposal for the management of dangerous people who have severe personality disorders (OFFICE AT HOME & Department of Health, 1999, also quoted in Davey, 2008). The controversy centered on whether it would be ethically suitable to convict individuals with feature that clearly point to risky to public basic safety (as it could be the analysis of psychopathy) if no crime has been committed.
In conclusion, I can say that both dynamics and nurture work to shape each other and producing in some individual hostility, but that the entity of the respected role is not yet determined. Considering the number of factors involved in producing aggressive behavior, and the difficulty of the connections among different causes, I would contemplate it more appropriate to refer to them as "risk factors" rather than triggers. This bottom line is strengthened by the observation that none of them of the factors has been found to unequivocally determine aggressive behavior in every individual afflicted by that specific factor. If the study on mother nature or nurture in hostility is conducted with the aim of finding ways to reduce the chance that aggressive or violent tendencies is displayed, this research field can be made free from the suspicion of possible unethical application. This means that parallel research is needed on the treatment of the risk factors, where treatment include pharmacological and psychotherapeutic treatment, but also measures at educational and cultural level as method of prevention.