Lecture 7: Psychological and Biological Theories of Crime

Welcome to the seventh lecture in the undergraduate criminology course of the University of Maine at Augusta. This week, we consider biological theories of crime. As a sociologist, I am inclined to look to social structure for explanations of criminal behavior, yet despite easily mocked early biological theories of crime there are growing indications that something about the physical nature of our bodies leads some of us to be more susceptible to crime than others. While sociologists like myself are more inclined to explain crime in terms of social circumstances surrounding individuals than on the basis of what’s going on inside those individuals’ heads, in another realm of social science psychologists mine the rich vein of complex, twisting human thought. This week, let’s set sociology to the side and consider both the psychological and the biological basis of crime.

This week’s lecture assumes that you have read Chapter 6 in Frank E. Hagan’s Introduction to Criminology; I also strongly recommend that you listen to Hagan’s special podcast recorded for this chapter. Our lecture subjects this week are:

Exam Results: Overall, Impressive

I’ve just finished grading the first set of exams as they’ve come in from across the state of Maine and a few other places around the nation, and I am glad to see the results overall. The mean score among students stands at 76.7%, but this is slightly misleading because the very poor performance of a few students brings that average down. More telling is the median score of 80, which indicates that half of students earned an exam score of 80% or more. Furthermore, the most common (“modal“) exam result was in the B range:

Grade Distribution for Criminology Exam 1 Fall 2016

If you are one of the many students in class who has earned a high score on the first criminology exam, congratulations to you! If, on the other hand, you are among one of the handful of students who has failed the exam, please be aware that this is an atypical result and indicates that you need to drastically change some aspect of your studying in the course to succeed. If you have failed the exam and are unsure what you need to change, please get in touch with me and I’d be glad to help you figure out the source of your difficulties. Remember that there are two more exams in which you may yet prove yourself.

The Use of Statistics in Criminology: Fact-Checking Hammers and Guns

Last week, you completed an anonymous mid-term course survey in which you indicated the sources of satisfaction and dissatisfaction with this course. Please know that I read each survey response thoroughly and think over your comments with care. I appreciate that you took the time to share your thoughts with the same care and thoroughness.  I especially appreciate the student who wrote to ask for more interactivity in the criminology lectures.  If this was you, I want you to know I read you, I hear you, and we’ll be introducing some interactive features to the criminology coursework starting next week.  Thank you for the thought!

I have to admit that one student’s response hit me in the academic solar plexus. S/he called me out for continually making reference to measurements of crime statistics in course lectures and questioned whether this was necessary or a reflection of the discipline of criminology. My answers are a resounding yes to both questions, if the goal of a criminology course is to reflect criminology as it is practiced and to cultivate critical thinking about crime.

The most prestigious journal in the field of criminology is titled, appropriately, Criminology. A recently published issue of Criminology features seven articles. Out of these seven articles, six used quantitative statistics as a central aspect of their inquiry. It is possible to engage in purely qualitative (non-numerical) research in criminology, but statistics are nearly ubiquitous in the discipline, which is one reason why I share some of them with you while teaching.

Another reason I share statistics on crime in lectures is that they are a good balance against a prevailing view in some quarters that crime is simply a matter of “common sense.” I hope the sense of crime as relatively defined has come through in the early weeks of this course, but to make that and other points convincing, it’s important to demonstrate that our “common sense” regarding crime is often off-base. I need to show you that what we think about crime and how crime actually plays out are often at odds, not just say that it’s so. That’s where reference to quantitative studies and the careful compliation of crime statistics become useful.

To provide an example of the usefulness of crime statistics in fact-checking our gut sense of the word, let’s think about hammers and guns. A commonly repeated claim on the internet related to weapons and homicide is that “more people are killed by hammers than by guns.” A few of the many sites online where this sentiment can be found:

“Far more people are killed by hammers in the US than by guns. When are we going to stop this senseless slaughter and outlaw hammers?” (MarketForum)

“If guns are inherently unsafe then so are hammers. Hammers were originally made to kill things. As man evolved he found other uses for them, just like guns. But their origins were used to kill things. Same with clubs. A tool for killing. But you take the same club and hit a baseball with it suddenly it goes from a inherently unsafe killing machine to a object that provides us a sport to play. The object has no moral’s or unsafe or safe features, and to attach moral’s, etc.. to an object and not the person is intellectually dishonest. More people are killed by hammers and bats than by the weapons the anti-gunners are trying to ban.” (DanCarlin.com)

“Obama and all those pushing gun confiscation in our government are lying to the American people about what their real motives are. They know that more people are killed by hammers, knives, ball bats and many other methods they are killed by guns.” (WND)

“You know that more people are killed by hammers than are killed by guns, right? Well, would society function fine without hammers?” (HotAir)

“Far more people are killed by hammers and blunt instruments than guns. Are you going to cry deeply and longingly to ban hammers?” (RefugeForums)

This is a strong sentiment that, if true, plays a useful role in policy debates regarding gun regulation. But is it true? Finding sources that claim it to be true makes for a weak test. A stronger test is made possible by the FBI’s annual Crime in the United States report, the latest of which was released just a bit more than a week ago. Expanded Table 8 (source | source) offers data on the count and relative share of homicides by various weapon types:

Homicides, 2008 to 2015 by weapon type


This data demonstrates that firearms in general kill many more people than are killed by blunt objects (clubs, hammers, etc.) or the use of a killer’s own body as a weapon (hands, fists, feet, etc.). But the FBI’s data allows us to look more closely at this question.  What kind of firearms are used in homicides in this country?  Again, from Table 8:

Firearm Homicides, 2008 to 2015

The overwhelming majority of firearm homicides are carried out using handguns.  This should be interesting to those who follow the gun control debate in this country, since the kind of firearms that are most often called to be banned — specialty rifles and shotguns — are not responsible for the majority of gun homicides.  The data also shows a recent uptick in homicide by gun over the last years, but one that only takes us back to where we were eight years ago. If the trend of 2015 continues as 2016’s results are released a year from now, there will be cause for concern. But those who claim that gun deaths are “reaching epidemic proportions” are not necessarily grounded in history.

Observable trends like these come to us thanks to the hard work of those who collect, compile and distribute national crime statistics. And although each method of observing patterns in crime has its drawbacks, consistencies in the overall picture contribute to a more nuanced basis for discussions about crime prevention. Whether or not you are now or will be employed in the criminal justice field, these statistics shed light on an a relevant and turbulent subject of discussion around many dinner tables in our nation today; developing a habit of systematic observation should be useful both there and on the job. No matter what side of the ideological spectrum you might find yourself on, crime statistics offer us something useful to consider and use.

Understanding Academic Integrity Violations as Psychological Acts, as Criminal Acts

Let’s transition in our discussion from the subject of homicide to a much less violent, but much more prevalent, crime: violation of academic integrity.

In various pieces of research carried out in the 1960s through the 2000s, between half and three-fourths of undergraduate students admitted to one form or another of violating academic integrity, some common examples of which include plagiarism, cheating on a test and falsifying information (McCabe et al 2001; Vandehey et al 2007). The University of Maine at Augusta has its own Student Academic Integrity Code that identifies standards, calls upon faculty to report violations of those standards, and sets up a judicial system to process students and punish them when they are found guilty of violating the standards. Every semester, I encounter students who cheat; I have and will forward students on to the judicial system within the university. Students won’t go to jail for plagiarism, cheating on tests or faking work, but the academic integrity code does create crimes of a sort.

Can cheating by students be understood from a criminological perspective? The answer is an unequivocal yes; there are criminologists who have published research doing exactly this. Over three decades of research, Michael A. Vandehey and his colleagues at Midwestern State University in Texas not only found that a majority of their students admitted to cheating, but that those students deployed the same neutralization techniques used by criminals to protect themselves from the stigma and shame of criminal behavior (Vandehey et al 2007). In responding to a hypothetical scenario regarding a student named “Jack,” students who admitted cheating were more likely than students who did not admit cheating to agree to each of the following statements:

"Jack should not be blamed for cheating if...

… the course material is too hard
… he is in danger of losing his scholarship
… he doesn’t have time to study
… the instructor doesn’t seem to care
… the instructor acts like his/her course is the only one
… his cheating isn’t hurting anyone
… everyone else in the room seems to be cheating
… the people around him made no attempt to cover their papers
… his friend asked him to help him/her cheat
… the instructor left the room
… the course is required.”

This indicates that these students have a consistent psychological approach to cheating, whether by themselves or others. David Matza and Gresham Sykes (1957) developed a theory of neutralization to explain how students breaking academic laws or criminals breaking more formal legal codes deploy one of five psychological techniques to explain away (“neutralize“) their actions:

  1. Denial of responsibility: “It wasn’t my fault!” Perhaps, the criminal might suggest, he was pulled into the act by others, or his poor upbringing is to blame, or he never learned any better at school, and that he was therefore helpless to resist the criminal act.
  2. Denial of injury: “No one was really hurt!”
  3. Denial of victim: “These weren’t innocent victims. They deserved what they got!”
  4. Condemning the condemners: “Who are you to judge me? We’re all criminals in a way, and the police are just as corrupt as I am!”
  5. Appeal to Higher Loyalties: “I had to hit that kid. He was threatening my sister!” “No one insults my church deacon and gets away with it.”

Nearly every one of Vandehey’s statements regarding academic cheating fits neatly under one of the neutralization categories described by Matza and Sykes — and it turns out that cheaters are more likely to agree with them than non-cheaters.

Is the psychology surrounding our cheating rational? In an attempt to apply deterrence theory to explain the prevalence of academic cheating, Cochran et al (1999) surveyed undergraduate students and discovered that a student’s perception of the severity or certainty of formal punishment for cheating did not influence the likelihood that she or he reported actually cheating. This result deals a blow to deterrence theory you learned about last week if we think of cheating as a form of crime. In other words, our acts do not appear to make logical sense.

Many of you are justice studies majors, likely to apply for jobs dealing with criminals in the criminal justice system. As you proceed to that future, remember that criminals are not just somebody else, a “them.” You may not individually cheat, but according to the best available studies a majority of your peers have cheated at one time or another. The criminals are an “us,” too.

How Biological Criminology Got Its Bad Name: From Phrenology to Naked Undergraduates

n image of phrenology from Webster's Dictionary, Circa 1900It is easy to ridicule and detest early 19th and 20th Century biological theories of crime because they actually are fairly ridiculous and detestable, at least from our current historical perspective.

Franz Joseph Gall’s theory of phrenology, according to which bumps and depressions on the skull could predict character and therefore criminality, is mismatched with modern knowledge of the brain. Gall (1835) supposed that the brain was subdivided into dozens of “organs,” each associated with a character trait such as murderousness, kindness or courage. Gall’s idea was that depressions or bumps indicated an under- or over-developed “organ” of the brain, and therefore indicated a propensity to kindness, courage — or murder. It’s an interesting idea, but it just doesn’t match at all with current knowledge of the brain. Phrenology is therefore easily dismissed as a biological theory of crime — and if we equate biological theories of crime with phrenology, we might dismiss biological theories altogether.

Less than a century ago, Earnest Hooton used his position as a distinguished Professor of Anthropology at Harvard University to promulgate a different biological theory of crime, one based on the idea that biological differences between people of different national origins are physically consistent. According to Hooton, these biological differences among ethnic groups lead to different propensities to commit crimes (Hooton 1939; for an excellent review see Rafter 2004). As the illustrations you see below from Hooton’s 1939 book The American Criminal indicate, Hooton’s study of the association between physical type and crime consistently ranked Northern European ethnicities as the least criminal, and Eastern European, Southern European and African ethnicity as the most criminal. These just happened to align with the ethnic prejudices of the day in the United States:

Earnest Hooton 1939, Illustration 1

Earnest A. Hooton 1939, Illustration 2

Although Hooton declared his open opposition to the Nazi variant of theories of racial superiority and joined the civil rights organization NAACP to advocate for increased rights of racial minorities, he also declared his support for eugenics campaigns that developed policies to discourage those of supposedly less-superior genetic stock from having children (Rafter 2004). These eugenist policies, many of which were imposed in 20th Century America, included forced sterilization for supposed mental and social inferiors (Silver 2004). Hooton even proposed segregation of biological undesirables in separate areas where they could not dilute the purity of quality genetic stock:

"Criminals are organically inferior. Crime is the resultant of the impact of environment upon low grade human organisms. It follows that the elimination of crime can be effected only by the extirpation of the physically, mentally and morally unfit, or by their complete segregation in a socially aseptic environment." (Hooton 1939, quoted in Merton and Ashley Montagu 1940)"

Further, with William Sheldon, an professed racist and eugenist with Nazi sympathies, Hooton used tens of thousands of pictures of naked Harvard University undergraduates in a study that attempted to demonstrate the association of biological measurements with future criminal and other anti-social behavior (Chong 1995).

It bears noting that Hooton’s study of American criminals and the Hooton-Sheldon studies of body types were empirically flawed and have not been supported under review. The somatotype research has been evaluated, even by sympathetic biosocial researchers, as “marred by subjectivity… poor conceptualization, [and] operationalization” (Madden et al 2009: 400-401). Sociologists Robert Merton and R.F. Ashley-Montagu noted in their contemporary criticism of Hooton’s work that the differences Hooton supposedly uncovered between criminal and “non-criminal” American body types were nearly inevitable, considering that the group against which imprisoned criminals were compared was not a random sample of Americans, but rather a set of Tennessee firemen and Massachusetts militiamen. The firemen and militiamen were, in addition, older than the convicted criminals studied, producing physical differences associated with aging. As Merton and Ashley-Montagu point out (Merton and Ashley-Montagu 1940: 387), comparing criminals to these unusual and non-comparable groups would inevitably produce notable differences.

Furthermore, we might ask, which are the physical differences that indicate biological difference between criminals and non-criminals to Hooton? They are the differences Hooton finds. Yet Hooton made many biological measurements between criminals and non-criminals and did not find differences of many sorts, and occasionally found differences opposite to those his theory would have proposed, namely “ape-like” features of lower primates. When Merton and Ashley-Montagu analyzed Hooton’s data independently, they found that in a large number of cases the criminals Hooton studied were actually more likely to possess “biologically advanced,” less “ape-like” features than non-criminals! That Hooton ignored these examples and only chose areas of difference that aligned with his theory made it inevitable for him to “prove” his theory. To extrapolate from flawed sampling, using circular reasoning, and selective presentation of results to conclude that entire lines of descent are biologically programmed for criminal behavior is both logically and empirically unsupportable.

It is easy for us to reject these ideologically-driven, empirically unsupported and even morally distasteful attempts to explain crime according to biology — and it might be tempting for us to therefore reject biological explanations of crime altogether. But such a broader conclusion does not logically follow. Consider Aristotle’s early theories of cognition, which located all thought, feeling and soulfulness in the heart and supposed that the brain was merely a cooling mechanism for the heart (Gross 1995). Despite being a very smart fellow, Aristotle was wrong. Does this mean that neuroscience is bunk? Clearly not. The answer to early failure in studies of cognition, based on poor measurement and inaccurate supposition, was to engage in more thorough and detailed study. And so the answer to early failure in biological theories of crime is not to avoid studying the subject altogether, but to set aside biased measurement and wild supposition in order to more carefully study the role biology might play in crime.

The Explanatory Power of Lead

One traditional failing of biological criminology has been to equate biology with heredity. As Hagan explains in Chapter 6 of your textbook, modern biosocial approaches are more liable to study the interaction of the human body with the environment surrounding the body in producing criminal behavior. One especially interesting line of recent research has to do with exposure to lead and its effect on criminal behavior. In an investigation published earlier this decade in Mother Jones, Kevin Drum summarized research on lead and crime. His review of the literature suggests that anti-crime efforts are missing the mark if they ignore pollution.

Consider the U.S. violent crime rate per 100,000 people as measured by the Uniform Crime Reports and reported in the FBI’s Crime in the United States (and generally confirmed as a trend over time by data from the National Crime Victimization Survey):

United States Violent Crime Rate per 100,000 population, 1960 to 2015. Source: FBI Crime in the United States report on Uniform Crime Report data tabulation.

Why did the crime rate go up so strongly from the 1960s to the 1980s, then drop just as noticeably from about 1990 onward? According to Drum and the criminologists he cites — including Mielke and Zahran (2012), Nevin (2007) and Reyes (2007) — economic explanations don’t wash — we’re currently in the middle of a long “Great Recession,” after all, and crime rates continue to fall. Similarly, the idea of a “drug wave” hitting the United States in the 1960s and 1970s sounds like a possible explanation, except that according to the National Institute on Drug Abuse drug use hasn’t been declining over the last decade, over a period when it appears that crime has been on the decline:

Past-Month Use of Selected Illicit Drugs, 2002-2013

What is the one trend that best appears to fit the national rise, then decline, in crime? Lead exposure. In the mid-20th Century, Americans were exposed to significant amounts of lead due to additives in gasoline. In the 1970s and 1980s, these additives were removed. Add a lag time of about 20-25 years to allow vulnerable exposed children to have their brains impacted during development, then grow up to hit the young-adult criminal phase of their life cycle, and the lead-crime curve almost perfectly matches the rise and fall of crime over time.

Reyes (2007) goes into greater geographic detail than this, looking at crime levels in different states within the nation, and finding that lead levels in the 50 states predict varying levels in crime across the 50 states. Mielke and Zahran (2012) zoom in for even greater geographic detail, looking at six major American metropolitan areas over 35 years. They find that changing exposure to lead dust explains changing levels of criminality between the cities, and within the cities over times, even when controlling for intervention efforts by the cities such as education, policing and incarceration, and when controlling for economic conditions within the cities as well. Mielke has further examined the city of New Orleans and found that varying levels of lead exposure in a neighborhood there — not economic conditions in a neighborhood — best explain differences in criminality between neighborhoods (Drum 2013). Nevin (2007) looks at the changing levels of lead not just in the United States but in other major industrial nations around the world. Due to variation in industrial practices and regulation between countries, levels of lead peaked at different times and fell at different times as well. When allowed to lag by 20-25 years, the time for young children to grow into young adults, the rise and fall in crime in each of the countries closely matches the rise and fall in lead exposure.

This is a biological effect on crime that has little to do with genetics, and a great deal to do with the decisions we make about our policy priorities. If lead produces criminality, and we care about fighting crime, and we can reduce lead in our atmosphere, what would happen if we “cleaning up our urban neighborhoods” stopped meaning the detention of street people and started meaning the cleaning of our soil? If we believe Drum, Miekle, Nevin and Reyes, it might produce a larger effect.

Activity for the Week

To receive credit for this week’s activity, first visit the page http://jamescookuma.com/criminology/which-of-these-people-has-been-convicted-and-for-what-crime/ to review photos of various people and guess whether they are convicted criminals, and if so for what crimes. Then log in to Blackboard and register your guesses by visiting “Activity #7: Biological and Psychological Theories of Crime” in the “Activities” section of our course’s Blackboard page.  Write down all of your guesses for all persons on that page (Persons A through R!).  Is each one a criminal?  If so, what do you think his or her crime was?  You will get full credit for your activity, regardless of whether your guesses are correct.

Activity 7 is due by the end of the day on Sunday, October 16.


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