Homicide Adaptation – Evidence presented by Duntley and Buss


This paper aims to provide an understanding of homicide adaptation through an analysis of the evidence presented by theorists, Duntley and Buss. To do this, a definition and elaboration of homicide adaptation theory will be provided. This concept will also be evaluated through cost-benefit analysis, special design features and comparative analysis, to elucidate its efficacy in determining why human beings commit murder. This paper will also provide insight into the potential limitations and loopholes that exist in the evidence presented by theorists to prove that homicide is an evolutionary adaptation.

Read also Index Crimes Comparison – Evaluating Rates of Homicide, Robbery and Rape in United States, Canada and Germany for 2012


Through the course of history, human beings have been involved in recurrent conflict with each other over reproductive partners, reputation, social status and resources (Duntley & Buss, 2008).  Homicide adaptation proposes that this constant conflict created psychological processes that allow human beings to entertain homicidal ideations. These ideations are activated in specific instances where a definitive solution to conflict can only be arrived at by killing. Once a rival is dead, they are no longer a threat to the killer’s reputation. Moreover, they cannot steal resources and cease being a plausible rival over romantic partners.

Read also A Theoretical Perspective of Crime – Homicide

These potential benefits to killing led to the selection of psychological adaptations for killing in specific conditions. Homicide adaptation theorists Duntley and Buss, posit that these psychological adaptations led to the development of a variety of motivational and computational systems that allow the selection of homicide as the most plausible alternative in conflict situations (Duntley & Buss, 2008). Due to the proposed benefits of killing over non-lethal violence, natural selection would have favoured individuals who possessed these psychological adaptations. Thus, human beings engaging in behaviour that resulted in the death of other individuals in case of conflict were preferred during natural selection.

Read also Abandoned Heart Homicide and Involuntary Manslaughter Essay

Analysis of Evidence Theorists, Duntley and Buss

To understand homicide adaptations, one must first understand adaptation and the peculiarities that qualify homicide as an adaptation. An adaptation is best defined as a trait or characteristic of a particular species that came into existence because it facilitated reproduction during a specified period in evolution. This trait was, therefore preferred during the process of natural selection and was inherited through subsequent generations (Duntley & Buss, 2008). An array of tools for the identification of evolutions have been identified. However, for the purpose of this discussion, evidence of homicide adaptations shall be evaluated using cost-benefit analysis, unique design features and comparative evidence from other species.

Cost-benefit analysis aims to establish the extent to which homicide improved reproductive success for individuals who possessed the necessary psychological processes to entertain and act on homicidal ideations. A trait is only favourable during natural selection if its presence brings about more benefits than challenges in its respective environment compared to similar traits. According to Duntley & Buss (2011), the potential benefits of killing are so substantial that they outweigh any reason to remain skeptical that homicide was preferred during natural selection. These benefits include, but are not limited to; eliminating sexual competitors, gaining resources, access to a wider selection fo fertile mates, protecting resources, territory, reputations, food, eliminating relatives who with little genetic fitness and preventing exploitation and injury of self, allies and relatives. On the other hand, homicide carries the potential risk of injury and death at the hands of a rival, which may result in; damage to allies, relatives and mates, loss of reproduction. Simply put, the homicide victims gain will often directly translate into the perpetrator’s gains.  

Read also Crime and its Elements

Adaptations are characterized by their inherent possession of non-random coordination between phenotypical properties and the environment which promotes reproductive fitness among species. According to Duntley & Buss (2010), homicidal adaptations are only activated when individuals face problems that can only be solved through killing such as threats to mates, territory, resources and reputation. Moreover, homicide relevant information can only be acted upon once the physical formidability of the victim and the likely consequences of the murder have been taken into account. If this evaluation will provide the individual with information on his ability to fend off his attacker and the potential costs of killing him, such as likely retribution from allies and relatives.

This evidence implies that homicide is a non-random action resulting from complex psychological processes that occur in a highly coordinated and effective manner. According to Duntley and Buss (2010), evolved the presence of homicidal fantasies best explains cognitive design for homicide. Fantasies provide a duration of planning. This planning involves consideration of likely scenarios where killing would be most effective, evaluation of the benefits and determination of viable strategies that would eliminate the potential costs. Individuals who could activate these fantasies in response to threats within the environment would have been preferred during natural selection over those that could not.

Comparing human evolved traits in human beings against those in other species to determine whether correlations exist between characteristics should reveal whether specific features occurred as a result of natural selection or were simply by-products of other adaptations. According to Duntley & Buss, Several species engage in conspecific killing in such predictable and coordinated processes that it is fairly reasonable to assume that they possess adaptations to kill. For instance, lions, wolves, hyenas and cougars have been known to kill infants belonging to rival males (Ghiglieri, 1999). The presence of conspecific killings is also well established in primate species such as chimpanzees, as well as gorillas. Researchers have also uncovered evidence of cranial trauma on ancient fossils that is consistent with death in the hands of fellow humans. Although the presence of homicide adaptations in other species does not necessarily imply that such adaptations exist in humans, it does provide an additional reason to be less skeptical that it does.

Limitations of homicide adaptation theory

The explanation for homicidal ideation provided by homicide adaptation is not without its pitfalls. Although the benefits of homicide seem to outweigh the costs, they cannot be evaluated adequately without comparison to those that could be obtained through alternative strategies. For instance, consider a dispute over reputation, it cannot be argued that murder would have provided a better solution than say, a powerful threat. While death would have eliminated the rival, a threat may have instilled fear, prevented future aggression from the rival and possibly his entire group (Durrant, 2009).  

Moreover, in a group setting, the killing off a rival member along with his/her family may have reduced the group’s success at hunting for food and defending themselves from external aggression. According to Duntley & Buss (2010), the widespread existence of homicidal fantasies constitutes reasonable proof that there are specific evolved cognitive processes related to homicide that exist in every human being. However, it would be ignorant to assume that the numerous fantasies human beings engage in are evidence evolved adaptation for the action fantasized about. If this were so, then it would be almost as accurate to posit that human beings have adaptations to suicide.

Furthermore, idly fantasizing about homicide does not necessarily mean that an individual will kill someone if he/she were in similar circumstances (Durrant, 2009). Finally, although several species have indeed demonstrated coordinated and predictable adaptations to killing, these adaptations exist due to socio-ecological contexts that are not present in humans. Male primates perform quick kills of children belonging to rival males. Death in stepchildren in human families often occurs as an unintentional consequence of neglect and constant abuse (Cavanagh et al. 2007). In spite of its many limitations, homicide adaptation presents viable evidence for why human beings kill and should be viewed as a viable explanation for why human beings kill.


This paper has presented an evaluation of homicide adaptation theory using cost-benefit analysis, comparative analysis and unique design features. Although homicide adaptation may not be able to provide conclusive answers in specific contexts regarding murder, it does give insight to the individual selection pressures that may have created cognitive processes within humans that favoured murder as a conflict resolution method. This new perspective is promising in its capability to provide a more wholesome view of murder than that provided by prior theories of homicide.

Share with your friends
Order Unique Answer Now

Add a Comment

Get Up 50% Discount on Your First OrderUp To 50% Off Your First Order Due in Less Than 48 Hours

Grab this first time Discount, and save up to 50% on your first Order Due in Less Than 48 Hours.