Skip to main content

Verified by Psychology Today


6 Reasons Why We Can't Stop Fighting

Is physical aggression always bad? The answer may lie in our ancestral past.

punching fist / pexels
Source: punching fist / pexels

Unfortunately, American popular culture has spawned a number of cringe-worthy memes in recent years—but "come at me bro" may be near the top of the list. The obnoxious phrase, popularized by Ronnie from MTV's much maligned reality show, Jersey Shore—who uttered it repeatedly when someone began taunting him on the boardwalk—basically means "try me." It is a quarrelsome signal that you do not want to initiate a fight, but if you are attacked you will be ready to fight back.

The First Ever Fight

The psychological mechanisms that govern aggression—a violent or hostile action toward another—may have evolved as solutions to a number of recurring adaptive problems faced by our ancestors. From the perspective of evolutionary psychology, the origin of aggression cannot be explained by one exclusive hypothesis. Instead, aggression might be an evolved solution to several adaptive problems (Buss & Shackelford, 1997). Resource protection and acquisition, intrasexual rivals, status negotiations, and partner sexual infidelity all stand out as possible adaptive problems that gave rise to aggression as a solution.

The problem for all of us living in a modern landscape that differs drastically from our past environments, is that the hoopleheaded, come-at-me-bro mentality does not line up nicely with with our notion of a civilized society.

1. Resource Control

Aggressive behavior, from an adaptive point of view, is beneficial if it improves the probability of survival and reproduction. Victims of physical attacks risk death, injury, harm to mates and offspring, loss of resources, and status. Aggression against attacking enemies would be an adaptive solution to the problem of resources being forcibly poached. Also, it can be used to develop a reputation that deters other possible attackers.

In addition to resource protection, aggression serves as a means of co-opting the assets of others (Buss, 1999). Adult forms of aggressive resource acquisition include mugging, bullying, and forming warfare coalitions to raid communities for land and mates.

Black and White Aggression / Pexels
Source: Black and White Aggression / Pexels

2. Intrasexual Rivals

Why is male aggression highest during late adolescence and early adulthood? One explanation is that competition for status and mates is most intense during this period. Men may become aggressive when social status is challenged especially in the context of competing for mates. Aggressive attacks on same sex rivals who are competing for access to opposite sex mates can range from verbal derogation to homicide (Buss, 1999). This hypothesis suggests that both men and women often share intense interest in outcompeting same-sex rivals.

3. Negotiate Status and Hierarchies

In many cultures, the victor in a physical fight may reap the benefits status elevation. Men who kill in war or expose themselves to dangerous combat are considered brave and may be rewarded for their courage. Modern spectator sports such as boxing, football, hockey, and wrestling represent a ritualized aggression that spoils the winner with fame and notoriety. The temptation to act aggressively in order to maintain status is also evident in controlled experiments. Griskevicius and others (2009) found that college men were more aggressive in face-to-face confrontations when they were motivated to increase their status on campus.

4. Deter Sexual Infidelity

Romantic partner sexual infidelity represents a specific context that can often heighten aggression. Male sexual jealousy is the leading trigger for spousal battery (Daly, Wilson, & Weghorst, 1982). Although obviously extremely abhorrent, it's well known that some males engage in abuse to deter wives and girlfriends from interacting with other men.

5. The Role of Testosterone

Numerous studies have found that blood chemistry can influence neural sensitivity to aggressive stimulation. For example, the well-known correlation between aggression and the male sex hormone testosterone appears to be a two way street. Higher levels of testosterone may cause dominant and aggressive responses, but aggressive behavior can also produce higher testosterone levels. Testosterone levels of sports fans surge after a victory and fall in the losing fans (Behnhardt, et al., 1998).

Similarly, assaults following rugby and soccer matches were more likely to be committed by fans of the winning team than the losing team (Sivarajasingam et al., 2005). Men who voted for the winning candidate in the 2008 U.S. presidential election showed higher testosterone levels compared to men who voted for the losing candidate (Stanton et al., 2008). In a rigged face-to-face laboratory experiment, socially anxious men displayed a drop in testosterone after losing a competition (Maner et al., 2008).

6. The Face of Aggression

During development the width-to-height ratio of male faces is affected by testosterone. Men with wider faces, reflecting higher levels of testosterone, are more aggressive both in and out of the laboratory. Wide faced college and professional hockey players spend more time in the penalty box (Carré & McCormick, 2008) and are evaluated as being less trustworthy and more aggressive by others in laboratory experiments (Stirrat & Perrett, 2010).


Aggression is a context-specific behavior that may have been an evolutionary solution to a number recurring problems of social living. From this standpoint, aggression is designed by natural selection to be sensitive to distinct adaptive problems confronted in distinct contexts—it is not a monolithic or inflexible strategy that functions blind of context.

Will we ever live in a violence-free world? It's hard to say, but if we are going to end aggression—or at least minimize destructive behavior—studying its origins is a good place to start.


Bennett, K. (2017). Adaptive function of aggression. In Zeigler-Hill, V., & Shackelford, T.K. (eds.), Encyclopedia of Personality and Individual Differences. Springer International Publishing AG. doi:10.1007/978-3-319-28099-8_1597-1

Buss, D. M. (1999). Evolutionary psychology: The new science of the mind (5th ed). New York: Allyn & Bacon.

Buss, D. M., & Shackelford, T. K. (1997). Human aggression in evolutionary psychological perspective. Clinical Psychology Review, 17(6), 605-619.

Carré, J. M., & McCormick, C. M. (2008). In your face: Facial metrics predict aggressive behaviour in the laboratory and in varsity and professional hockey players. Proceedings of the Royal Society B: Biological Sciences, 275(1651), 2651-2656.

Daly, M., Wilson, M., & Weghorst, S. J. (1982). Male sexual jealousy. Ethology and Sociobiology, 3(1), 11-27.

Griskevicius, V., Tybur, J. M., Gangestad, S. W., Perea, E. F., Shapiro, J. R., & Kenrick, D. T. (2009). Aggress to impress: Hostility as an evolved context-dependent strategy. Journal of Personality and Social Psychology, 96(5), 980-994.

Maner, J. K., Miller, S. L., Schmidt, N. B., & Eckel, L. A. (2008). Submitting to defeat: Social anxiety, dominance threat, and decrements in testosterone. Psychological Science, 19(8), 764-768.

Sivarajasingam, V., Moore, S., & Shepherd, J. P. (2005). Winning, losing, and violence. Injury Prevention : Journal of the International Society for Child and Adolescent Injury Prevention, 11(2), 69-70.

Stanton, S. J., Beehner, J. C., Saini, E. K., Kuhn, C. M., & Labar, K. S. (2009). Dominance, politics, and physiology: Voters' testosterone changes on the night of the 2008 united states presidential election. PloS One, 4(10), e7543.

Stirrat, M., & Perrett, D. I. (2010). Valid facial cues to cooperation and trust: Male facial width

and trustworthiness. Psychological Science, 21(3), 349-354.