Essays and Theories

Evolutionary Psychology and The Male "Criminal" Mind.
by
William A. Spriggs

"Ours is a world of nuclear giants and ethical infants.  We know more about war than we know about peace, more about killing than we know about living." 
Army Gen. Omar Bradley, addressing West Point cadets, 1952

In the past several years, studies intended to ferret out the factors producing the male criminal mind seem to have focused upon low serotonin levels, low standing heart rates, and high testosterone levels. These studies are being done as the social order seems to be crumbling beneath our feet. Our society, some social critics fear, is losing the battle of controlling and preventing violence in our culture.(See the entire June 14, 1995 issue of the JAMA, Journal of the American Medical Association which is devoted to domestic violence. See in particular Dr. B.S. Centerwall's article, linking violence to socioeconomic environment. P. 22) While politicians of the left and right cry that Hollywood, or the disintegration of the family, is to blame for the decline in morality, scientists, too, weigh in on the debate. Scientists, however, tend to believe that if they can just find the gene responsible for criminality, then violence will become a thing of the past.

What will be found, I believe, is that there is in fact more than one gene responsible for "criminal aggression," and that these genes act in concert according to the environment in which the "criminal" finds himself. In short, we will find that a stressful environment creates a responsive behavior adaptive to that environment. From the standpoint of evolutionary psychology, these behaviors, are innate, adaptive behaviors -- their motive is not the commission of crimes, but survival. We have a brain and genes that were suited for the savanna of 25,000 years ago, and we still carry them with us today. We must readjust our thinking to reflect that admission.

* * * * * *

As hunter-gatherers, our ancestors formed groups. We are social animals today because our hunter-gatherer ancestors found that, in forming groups, they could better provide for their own survival. In a group there are more eyes and ears to watch and listen, and more noses to smell for potential predators, an act of nature, or perhaps other tribes. In order to transmit the coming of a potential danger, our ancestors created cries in patterns by expelling air from their mouths. Later, these noise patterns were linked with hand motions as early sign language, which then developed into verbal language unique to the group. Additionally, by being in a group they found that they had a greater selection of females and males to choose from as potential mates. All of these factors gave our hunter-gatherer ancestors a common reason to be together: The social structure of the groupings provided better opportunities for food, mating, safety, and companionship.

There is no way to get around this: the majority cultural patterns of present-day males in society lead evolutionary psychologists to conclude that our ancestral hunter-gatherer social groups were dominated by the physical strength, stamina and stature of the males. Before plant domestication some 10,000 years ago, fruits, berries, and nuts were not always easily available. This problem-solving ability of learning to capture small animals, and then larger ones insured our survival as a species. Our ancestors survived on their hunting abilities, assisted by an adaptive "aggressive" tendency necessary to accomplish the task. Once the cultural habits of male dominance were established, they were reinforced by further continued successes; in most but not all cases, success in using force over females to dominate gene distribution. The adaptive response of the female to this aggressive tendency was to adapt to the trait, thus gaining resources for her children. Another possibility is that the male became aggressive to gain favor of the female and thus pass on his genes. Finding great advantage in this arrangement to their gender, males dominated by the use of strength and stamina in a harsh and unforgiving world. (For a first-class observational commentary on sexually abusive males in our society today compared with our present day primate cousins, see "Apes of Wrath," by Barbara Smuts, Discover magazine, August, 1995). Since evolutionary success was built on the foundation of the aggressive male and responsive female, evolution continued to favor those social groups dominated by "naturally selecting" cultures in which this aggression and response dominated. However, because of child-rearing and the delicate task needed, males took the most and gave little back. Then, as today, males control most of the resources and they use those resources in a variety of manipulative methods. The species survived, and the survival behavior became embedded into genetic instructions to ensure that survival.

This, of course, is not to posit the inevitability of the continued dominance of this male "aggression.." Just because this direction of evolution allowed us to arrive at this place in time successfully, does not mean it has to continue.

But what led us down this genetic path? In any group, conditions vary, leading to various cumulative results. Some male hunters were more successful then others. Some clans had numerically more sons, sons that were engines of resource acquisition and, hence, an advantage in accumulating resources. (Also most likely giving rise to the concept of males as more desirable in childbirth in various cultures). Those combining the traits of strength, stamina, and cunning began to out-perform and bring back more catches than others. Their stature grew, that of others withered. This male dominance in hunting led to battles for dominance in territory and the selection of females both essential elements in gene transference. In most cases, this led to the creation of a single dominant male who controlled access to the females; if other males wanted access, they found it necessary to form an alliance with the dominant male. Thankfully, this sexual dominance was eventually cracked by the cunning resourcefulness of the females. To do this, the females had to most likely "cheat" on their dominant male by stealing away from the group for a dalliance with a non-dominant male (For an excellent study on this, see "The Importance of Being Sneaky," by Glen Zorpette, Scientific American, June 1995 the Puerto Rican study of the rhesus macaques).

* * * * * *

Today, there are three major internal indicators that scientists are focusing on which seem to contribute to male criminality. They are: 1) low serotonin levels; 2) low resting heart rate; and 3) high testosterone levels.

First, I want to go over the facts that I have gathered detailing serotonin levels in various males, females and lab animals.

Serotonin levels are lowest in adolescent males.

Serotonin levels are 20% to 30% lower in men than women.

Serotonin levels are lower in lab animals subjected to stressful environments.

Serotonin levels are high in newborns.

Serotonin levels rise again with maturity. (Discover, November 1994).

Serotonin levels are low in depressed individuals

Serotonin levels are low in lab animals with increased sex drives (Time, June 12, 1995)

As of the writing of this theory presentation in June 1995, low serotonin levels appear to result in increased sex drive and, sometimes, homosexual couplings in lab animals given drugs and special diets to reduce serotonin levels (Time, June 12, 1995). The latest information concerning homosexual linkage is another hole in the serotonin theory. It now stands beside non-aggressive depression as a contributor to low serotonin levels. I will try to explain these anomalies in a moment.

Now, though, let us move on to low resting heart rate and its link to criminal tendencies. In study after study, results have shown that petty criminals tend to have a significantly lower pulse rate than do their well-behaved counterparts. Psychologist Adrian Raine seems to think that lower heart rate probably reflects fearlessness. (Psychopathology of Crime, by Adrian Raine, Academic Press, 1993, as paraphrased from Scientific American, March 1995).

Finally, high concentrates of testosterone have been found in those men who are more likely to have committed crimes of a violent nature. Testosterone levels are responsible for building muscle mass and strength. Scientific studies abound establishing the link of testosterone to criminality. Those of us in evolutionary psychology believe it is simply a "cunning maneuver" to avoid and control the more physically stronger testosterone-high male by weaker males. The objective would be to force society to look at overwhelming evidence of the link of criminality and high-testosterone and hence derogate the "fitter" male into oblivion and away from the females.

* * * * * *

My theory, as seen through the eyes of evolutionary psychology, suggests that serotonin depletion in the "criminal" male is most likely "time-released," similar to puberty. This aggressiveness is activated by a brain that has adapted to its own unique environment. Lower serotonin levels in males causes "outward aggressive motion" to increase the "fight" or "aggressiveness" necessary to capture or kill food for the tribal clan, help establish territory area, and establish ranking through the acquisition of resources. In simpler terms, low serotonin levels, low standing heart rates, and high testosterone levels merely mean that "aggression" was and is used to obtain resources which ultimately attract the female. The primal motivation is not to commit "crime" but to attract a mate in order to pass one's genes on to the next generation.

I surmise that the three indicators of "criminality" are activated by a cascade effect. Certain genes turn off and some turn on in order to produce the desired cryptic gene messaging to the brain. Today, as then, the most likely cascade scenario would depend on your socioeconomic level and your immediate safety factor. Hence the "aggressive need" of your neighborhood South Central L.A. or, alternatively, Chevy Chase, Maryland would determine and affect your serotonin levels. Your "aggressive need" most likely would be greater in South Central L.A., where the stressful environment would be less secure than in the wealthy, peaceful, Washington D.C. suburb. Both, however, are still activated by mate attracting "requirements."

As for the two apparent anomalies, the linkage between low serotonin levels and homosexual couplings, and low levels and depressed individuals: until I do more studies to strengthen my theory, it appears that these two behaviors are a reverse mirror behavioral response; they are the exact opposite from those expected. My speculation is that they are "deviant" behavioral responses to "fill-in" a blocked path -- i.e..depression is really inward aggression toward one's self vs. outward aggression. Homosexual couplings still means "time to mate" in DNA instructions, but the chemical push to mate leaves the details to your higher conceptual imagination when "normal" avenues are blocked. Such as male inmates of prisons and priests forbidden to copulate. (I call this simply -- The Prison and Priest syndrome).

To sum up, serotonin levels are lower in men because 30,000 years ago they usually did the hunting. Serotonin levels are lower in animals subjected to stressful environments because hunting is a violent exchange between prey and predator. Serotonin levels are high in newborns because they do not hunt. Serotonin levels are lowest in adolescents because 25,000 years ago, the best hunter had the best future. This corresponds with studies that show increased sexual activity and low serotonin levels in adolescents. Infants do not find and locate mates; males in the 16- to 26-year-old range do. Thirty thousand years ago, an old man was 35; hence the increase in serotonin levels and "less aggressive" tendencies when our present day males reach maturity. Do you need empirical evidence?  Just look at automobile insurance rates for single males between the ages of 17 and 25. Why are the rates higher?  Because single young males have the most accidents.  And why do they have the most accidents?  Because they are most aggressive drivers found on our nation's highways.  As for the mature male, remember that most professional athletes retire by the age of 35 to 37 years of age.

Now, let's take low standing heart rates and high testosterone levels, both of which seem to be present in the modern day "criminal" man. As for a low heart rate: the successful hunter had to learn not to move, breath heavily, or make any noise; any of these would alert prey and thus lessen the possibility of the successful kill. But, the hunter must still be ready to act "aggressively" in a moment's notice to catch the startled prey. The usefulness here of a high testosterone level is fairly obvious: muscle mass and stamina helped in the "catch." The bottom line is this: the better hunter our male "criminal" ancestor was, the more resources he acquired. The more resources our long ago male gathered, the better the chance of obtaining a higher-ranking female who would be lured by his comparatively larger cache of resources. Men were aggressive then, and in most cases are aggressive today because it is this "aggression," that helps to acquire what females want most: resources. This is as true of a "successful" young male lawyer in Washington D.C., as it is of a gang warlord in South Central L.A. Resources get the chicks, which passes the genes. No one has explained it better than David M. Buss, in his book The Evolution of Desire (Basic Books, 1994 p. 213). Also see Mesquida and Wiener, Ethology and Sociobiology, Volume 17, Number 4, July 1996, with their paper: Human Collective Aggression: A Behavioral Ecology Perspective.


In conclusion, I feel very strongly that this theory will stand the test of criticism. If we take a cultural photograph of the planet in 1995, we see a world dominated by males. It is from this point that we can follow the path backwards to our primate cousins and see similar behavior patterns. Again, this does not mean that the dominance of males will last forever, but only that such dominance is the reality today. It is, however, a mistake to conclude that the young males in our inner-cities are more criminally prone and "aggressive" than their wealthy gender cousins in safe suburbs. Both are hunters--only the environment is different. (Also see "It takes more than just a hormone to make a fellow's trigger finger itch." by Robert Sapolsky, March 1997 issue, Discover magazine.)

Origin: July 1995

Updated, Sept. 18, 1999

Former Title: Low Serotonin Levels, Low Standing Heart Rate, and high Testosterone Levels in the Male "Criminal" Mind. A theory derived from Evolutionary Psychology.


To further advance your studies of the male "criminal" mind, and the male gender in general, I have added a listing of mental disorders taken from the DSM-IV, The Diagnostic and Statistical Manual of Mental disorders, Fourth Edition that appear to visit the male gender in larger percentages than found in the female gender.   The Original list that I complied consisted of 42 disorders, but I  reduced the list to those disorders that I thought had a much greater impact on the male gender.  The final list came to 26.  Caution should be taken as they are presented out of context and should be considered speculative in nature when combined in their totality.  Please take particular note of the disorders that occur in the 16 to 26 years of age range and then rethink my above essay.

On the left, you will find the page number in the DSM-IV with the corresponding mental disorder.  Since this is a commercial web site, we have avoided quoting the manual word for word in its description of the the disorder.

Page 49                 Reading Disorders          Males are 60 to 80% more likely to be diagnosed with the Reading Disorder than females.

Page 64                  Stuttering                         Males are three times more likely to stutter than females.     

Page 68                 Autistic Disorder             Four to five males are more likely than one female to be Autistic.

Page 82                 Attention-Deficit/Hyperactivity Disorder             In the general population, the male is four times more likely than the female to have ADD/HD.   In clinical settings, the male is nine times more likely than the female to be diagnosed to have ADD/HD.

Page 88                 Conduct Disorder          Males are much more likely than females to have problems in school or the work environment involving discipline, vandalism, or fistfights.

Page 102                Tourtette's Disorder (rapid movements called tics).             One and a half to three males are more likely than a female to have this disorder.

Page 120                 Stereotypic Movement Disorder           More commonly know as head banging, this disorder is diagnosed in three males for every female.

Page 188                Substance-Related Disorders                In almost every drug related substance, the male is more likely than the female to be affected by this disorder.  In an almost exact matching of the primary hunter-gatherer age group of our own primal ancestors, the ages seem to be most prevalent between 18 and 24 years of age.  It is my strong opinion that the lack of resource opportunities is in direct proportion to substance abuse.  

Page 235                 Hallucinogen Use and Intoxication             Males between the ages of 18-25 years seem to be three times more likely than females to use hallucinogens.

Page 241                 Inhalant-Related Disorders                  70% to 80% of emergency room visits involve males in their adolescence.

Page 254                  Opioid Dependence   For every three to four males, only one female seems to be dependent on opidids.  Usage after the age of 40 has been called "maturing out" in the DSM-IV manual, but if you read my essay above, you will find that this merely reflects the rising of serotonin levels in the aging male that produces this "mellowing out."

Page 260                 Phencyclidine-Related Disorders (PCP)            As with page 188, males account for about 75% of emergency room visits.

Page 522 -- 524     Paraphilias                This is the most startling section of the study.  All the Paraphilias below are almost exclusively male in their behavioral mechanisms.  The only exception appears to be Sexual Sadism, in which for every 20 males, only one with the disorder will be female.  All of the behavior mechanisms are meant to sexually arouse and or enhance sexual orgasms. They include:

Page 535                 Gender Identity Disorder                Males with this disorder outnumber females by 5:1 in general; 2 or 3:1 in clinical settings.

Page 559                Primary Hypersomnia (excessive sleepiness)             They syndrome known as Kleine-Levin is diagnosed in three males for each female.

Page 571                 Breathing-Related Sleep Disorder                 Commonly known as snoring, this disorder is about eight times more common in males than in females.

Page 614                 Pyromania                 Pyromania is much more prevalent in males than in females.  It is my strong opinion that the behavior shows up more in males of lower socioeconomic and learning dysfunctional young males as a method to receive attention from adults as a message that they are shunned by their peers because of their academic difficulties.  The physical act of Pyromania is easier to accomplish (to them) than academic achievement.

Page 660                 Nacissistic Personality Disorder                This disorder is most common in males, with the male-to-female ratio of 2 or 3:1.  The disorder is the need for admiration from others; lack of empathy to others, and thought scenarios of grandiosity.

Page 671                 Obsessive-Complusive Personality Disorder                There are approxiamately two males to every female with this disorder


Addendum, Sept. 18, 1999

I suppose that I should balance the augment of the male "criminal" mind and state that there are females who do commit crimes, but the overwhelmingly statistical evidence leaves little doubt about the males dominance in the crime statistics. In the United States alone,

Now that is violent crime. There still remains the statistical analysis of non-violent criminal activity, which although are not as destructive as violent crimes, are still behaviors that we in our moral societies have judged to be criminal in their actions and have passed laws to prevent those behaviors by passing judgement in courts of laws.

In only two categories do females lead males in "criminal" activity; running away from home, and "commercialized vice." Although not listed, I personally believe that in the latter "crime," the female is helped and strongly influenced to commit the crime by a male "protector" and " solicitor agent."

Now, it should be appropriate at this juncture to bring up the argument "that minorities commit more crimes then the dominate and controlling phenotype, (read white males of European descent). "well, just look at the stats.....crime is highest in inner-city areas and they all live there!!"  That is correct.   However, now with GIS (Geographic Information System) software now available now it is possible to find definitive statistics that most crimes are resource accumulation related.

Richard Wrangham and Dale Peterson, Demonic Males, Houghton Mifflin, New York, NY, 1996 pp. 113 and 114.

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