Stalking the mark of Cain.

• Author: O'Neill, Michael Edmund
• Position: Tests to determine a propensity to commit violent criminal acts.

The Old Testament records that Cain, the first-born son of Adam and Eve, murdered his younger brother Abel in cold blood. (1) As a consequence of this sin, God cursed Cain to live as a "fugitive and a vagabond" forever after. (2) Cain responded to his plight by crying "every one that findeth me shall slay me." (3) The Lord thus proclaimed that "whosoever slayeth Cain, vengeance shall be taken on him sevenfold." (4) God subsequently set a mark upon Cain, "lest any finding him should kill him." (5) Behavioral psychologists have long sought to pinpoint a similar sort of "mark" in modern day criminals--namely, a genetic or other biological marker that could serve to identify those who may have a propensity to commit violent criminal acts.

Efforts to establish a link between criminal behavior and biological or environmental "causes" are nothing new. Cesare Lombroso, the nineteenth century Italian criminologist, was perhaps the first to argue on an allegedly scientific basis that criminals are born, not made. (6) He drew on the emerging theories of evolution and genetics--as well as the pseudo-science of phrenology--to proclaim that individuals possessing a "criminal mind" might be identified by certain peculiar deformations of their skulls. Although Lombroso's theories did not withstand the test of rigorous analysis, psychiatrists (among others) are revisiting the possibility that certain criminal behaviors may possess a biological origin.

While sociologists have long advanced environmental and other sociological theories (poor nutrition, poverty, racism, etc.) under the rubric of "root causes of crime" to explain criminal behavior, (7) efforts to identify biological causes for explaining this same conduct have long been viewed as taboo. (8) One's environment, or so it has been perceived, is inherently manipulable, thus an individual's circumstances may be altered to effect a change in the individual's behavior. Identification of an environmental "cause" influencing behavior thus does not challenge prevailing orthodoxies that view man largely as a product of external forces. The concern is that biology, unlike environment, is not quite as easily manipulable (although that notion is itself coming under scrutiny) and thus places the individual at the mercy of her genes. As a result, critics of biological research into human behavior have regarded as suspect any claim that biology forms the basis for behavior.

Nevertheless, with the rise of evolutionary psychology, biological psychiatry, and more sophisticated tools for understanding and mapping basic brain activity, biological theories of human behavior--particularly violent, impulsive conduct--are resurfacing. (9) It is hardly news that the brain has something to do with the way we think and act. Only recently, however, have researchers begun to identify and to understand certain neurochemical and neurophysiological correlates of mentation and behavior. (10) The resulting body of knowledge, though in its own right profound, is nevertheless still far from answering many fundamental questions about the causes of criminal behavior or from providing us with a reliable mark of Cain to ferret out those likely to engage in criminal conduct. The prospect that such findings may be in the offing, however, requires us to grapple with some of the most fundamental principles by which we assess--and ultimately criminalize--certain types of behavior.

In this essay, I hope briefly to raise several of the more fundamental issues raised by this burgeoning understanding of the mechanisms influencing human behavior--specifically, questions surrounding the meaning of criminal intent and the moral justification for imposing punishment. If, for example, we are better able to understand the biological causes for certain types of behavior, will we be forced to modify ideas of freedom and responsibility because the principal functions these notions serve no longer accurately reflect our understanding of human behavior in light of our discovery of the biological antecedents of decision making? And if we are able to pinpoint behavioral triggers over which we may exercise only the most meager of volitional controls, may we be compelled to rethink our conceptualization of punishment? It is to these questions I will now turn.

1. BIOLOGY AND THE FUNCTION OF THE CRIMINAL LAW

   The mere mention of the terms "biology" and "criminal law" within the confines of the same sentence immediately sets off alarm bells in the minds of some commentators. Identifying "biological" bases for criminal behavior raises justified concerns about racism, sexism, and what are perceived as attempts to relegate to the sidelines important environmental factors affecting human behavior. (11) Critics of such research argue that if biology determines behavior, then we are not only wading into a revival of the uglier forms of racism, but we might also be tempted to forgo social efforts to transform decaying neighborhoods, to rebuild impoverished schools, and to rehabilitate destitute individuals. An off-voiced concern is that if biology figures predominantly in governing behavior, such crucial social reform efforts will be stymied.

   While well intentioned, and doubtless cautionary about the errors and injustices of the past, it is my view that these criticisms reflect only part of the overall mosaic of understanding human behavior. The search for biological indicators leading to certain types of criminal behavior is important and something that will occur regardless of efforts to stop it. (12) The debate, oftentimes cast as one of nature versus nurture, has been transformed into how the interaction of nature and nurture may affect human behavior. Indeed, few would express the belief that biology is the sole factor in determining human behavior. Ultimately, the underlying biological basis affecting behavioral development cannot easily be disentangled from environmental factors. The medical community has come to accept that one often breeds the other. (13) The question is whether human behavior--for my purposes, what society chooses to label as criminal behavior--can be understood as the result of interplay among conscious choice, environmental factors, and basic human biology.

   While there are those who scoff at any notion of a biological basis for crime, let us consider two widely-accepted, well-demonstrated factors. First, males commit the overwhelming number of violent crimes the world over. (14) Whether one is reviewing criminological data from Japan, the United States, South Africa, Germany, or Brazil, this same constant holds. Even across these rich and varied cultures, men, and primarily men, are violent. Second, it is widely acknowledged that age plays a significant role in criminality. (15) Men between the ages of sixteen and twenty-five commit the vast majority of violent crimes.

   Neither of these "facts" is particularly controversial and both are recognized not only by researchers, but also by individuals engaged in the daily activities of life. When walking down a lonely, dark street in the wee hours of the morning, one generally has a markedly different feeling when confronting a group of young males than young females. Similarly, the presence of a lone male on the street often signals something very different from a male accompanied by a female.

   If we are willing to accept these two widely acknowledged notions, then why are we resistant to at least considering that biology, as well as culture, may play a role in the type of behaviors that appear to correspond with criminal conduct? Merely accepting the obvious gender role in criminality suggests that biology necessarily plays some part in criminality--even if it is biology as played out in the larger context of environmental influences. But the behavioral roots of violence may run even more deeply than mere gender. Recent studies of the behavior of twins in North America, England, and Japan have demonstrated that where an identical twin is a juvenile delinquent, there is a ninety-one percent chance his twin will be as well. (16) For fraternal twins, however, that correlation is only seventy-three percent, and it is even less significant for non-twin siblings. While studies of this sort are hardly conclusive, they at least suggest that we ought to pay attention to environment and biology in understanding certain types of criminal behavior.

   Behavioral studies aside, many of us have witnessed the devastating effects of depression, drug or alcohol abuse, mental illness, or senile dementia in our own families. It is not particularly uncommon for a family to witness the profound personality changes that an elderly relative may undergo during the onset of Alzheimer's disease. Similarly, families must work through the personality changes that often occur in a drug-addicted teenager or an alcoholic relative. In our normal family lives, we are often witness to the effects of illness, disease, and drug addiction on the behaviors and personalities of those whom we love. If we can accept, and seek to understand these more common-place problems, should we then turn a blind eye to the possibility that neurobiological factors may influence other sorts of behavior as well?

2. RECONSIDERING CRIMINAL INTENT?

   The principal difference between the criminal law and the civil law is the notion of mens rea--the criminal, or guilty, mind. (17) The question of the perpetrator's mental state is fundamental to virtually every malum in se crime that society chooses to punish. (18) The historical roots of a mens rea component in establishing criminal liability run deep and extend to the earliest known legal systems. Ancient Hebraic law, for example, drew a clear distinction between a person who kills another intentionally and one who kills not by "lying in wait" for his victim, but instead by having "God deliver him into his hand." (19) Building upon these ancient precepts, English...