The Making of the Mind: The Neuroscience of Human Nature (28 page)

The mirror neurons that enable the brain to recognize an action appear to capitalize on our uniquely human theory of mind. Because human beings are capable of understanding others as intentional agents, it is possible to recognize the intention behind the action. Suppose you observe a hand grasping a cup. Is the actor's intention to take a drink from the cup or to wash it? If the context shows the cup with a teapot, a plate of cookies, and a jar arranged for having tea, the action would then be linked to the intention of drinking. By contrast, if the context shows the cookies mostly eaten, the lid off the jar, and a soiled napkin under the teapot, then the action would be linked to the
intention of washing. Using fMRI, researchers measured the response of the brain to the context alone, the isolated action, and the action in context.
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By comparing the neural activity generated by each of these conditions, they were able to isolate a region in the right inferior prefrontal cortex—a region known for the presence of mirror neurons—that specifically recognizes the intention. For example, subtracting the activation found for the isolated action from the action plus, say, the washing context, the activated region still remaining would be the site for identifying the intention as opposed to the action.

A final facet of human empathy is the ability to regulate one's emotional response. When emotions are induced simply by watching another person experience pain or express sadness, the emotions must be modulated in order to feel empathy for the person instead of just getting caught up in the same plight. Part of this process of keeping our distance from the object of our empathy activates a region in the right hemisphere at the junction of the temporal lobe and the parietal lobe.
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The region is associated with self-agency. Another part explicitly aims to downplay the significance of the emotion “by denial of relevance (i.e., taking a detached-observer position) by generating an image of the observing self unaffected by the target…to reduce the subjective experience of anxiety, sympathetic arousal, and pain reactivity.”
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MORAL MUSCLE

At its root, morality requires a standard of proper conduct. Knowledge of good versus evil is part of our nature. If it were not, then moral judgment and choosing to do what is right rather than wrong would not be possible. But simply the knowledge of right and wrong is by itself insufficient for moral action. One must also be able to inhibit evil thoughts and not act upon them. Is not a person morally accountable for their actions if they know the difference between right and wrong but cannot avoid acting on an impulse to do wrong? Understanding fairness through moral reasoning is only part of the story. The ability to monitor one's behavior relative to a standard of conduct and to alter one's behavior to bring it in line with the standard is referred to by Roy Baumeister as “moral muscle.”
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Just as precursors were found for language in nonhuman primates, the
mirror neurons that link perception and action provide a foundation for the full scope of human empathy and morality. As already shown, human empathy builds on this foundation, adding advanced social intelligence and the human executive functions, which combined permit the reading of others’ minds and the taking of their perspectives. But another part of the modern mental ensemble also contributes. Our moral intuitions about what is right and what is wrong were passed down through the medium of language from one generation to the next for thousands of years in the oral traditions of countless cultures. Eventually, the socially transmitted moral codes became the basis for the written legal codes of Neolithic humans. Beginning with Babylon's Code of Hammurabi in the eighteenth century BCE, cultural evolution fueled by written language has brought us, thirty-nine centuries later, the legal systems of today. Contemporary national and international law reflect the confluence of language and morality that sculpted human cultures and histories.

A culture's standards of moral conduct often derive from its religious doctrines. The Ten Commandments of Judeo-Christian cultures reflect an admixture of theology and morality. Spoken by God on Mount Sinai (Exodus 20:3–17), the commandments provide rules for both humanity's vertical relation with God (e.g., “You shall have no other Gods before Me”) and the horizontal relations among people (e.g., “You shall not murder”). In addition to proscribing murder, God commands against committing adultery, stealing, bearing false witness against one's neighbor, and coveting anything that belongs to one's neighbor.

It was Christian theologians in the Middle Ages who delineated the Seven Deadly Sins. In each case, a clear standard of moral conduct was articulated, and human failures to conform to the standard were viewed as sins against God's will for humanity. Gluttony, for example, is an overindulgence of the human appetite for food or drink. Although the religious context of gluttony has faded in contemporary society, overeating and overdrinking are as popular as ever. The US Centers for Disease Control and Prevention reported that the prevalence of obesity in the United States rose markedly during the last decades of the twentieth century, with the most recent figures indicating that 35.7 percent of the adults over the age of twenty were obese in 2009–2010.
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Plentiful sources of energy-rich food, a largely sedentary lifestyle, and
excessive consumption have resulted in more than a third of the population meeting the body-mass-index definition of obesity. Neither greed nor lust are endangered either. The recent collapse of capital markets throughout much of the Western world in 2008 has painfully reminded us that greed reigns. However, it would be mistaken to think that greed in the twenty-first century is any more intense than in any past century. The crash resulted at least in part from an overemphasis on short-term profits that encouraged excessive risk.
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Surely, no one could seriously argue that human beings are more lustful today than they have ever been. Yet it is now much easier to document those lustful thoughts simply by recording the volume of Internet searches for pornography. Natasha Vargas-Cooper, writing in 2011 in the
Atlantic
, concluded that “pornography is now, indisputably, omnipresent: in 2007, a quarter of all Internet searches were related to pornography. Nielsen ratings showed that in January 2010, more than a quarter of Internet users in the United States, almost 60 million people, visited a pornographic Web site.”
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Sloth, wrath, envy, and pride round out the list of seven. It is safe to say that none are in any danger of extinction. The same kinds of failures of self-control described by theologians in the Middle Ages are, of course, very much part of human life today. The central point is that for human beings to conduct their lives morally, they must have knowledge of a set of standards. If societies tolerate or even condone gluttony, greed, and lust, then there is no basis for expecting people to exercise self-control. People in each generation assume the obligation of transmitting standards of conduct to their children through oral instruction. The written word, in sacred texts, in theological commentaries, in the law and in judicial records, not to mention in the advice columns of countless newspapers and magazines, also provides knowledge of the standards. Today, no less than in the Middle Ages, the concept of what is proper and fair can be readily obtained chiefly because of language. It is hard to imagine how human morality could have ever developed and endured without language to encode and store the standards.

Mental time travel also is central to the establishment of moral standards. It frees human beings from the present moment by reconstructing past events and imagining future ones, and it is therefore responsible for much good. Perhaps this ability to think prospectively as well as retrospectively enabled
early humans to conceptualize the notion of time itself. It is foresight in particular that has a role in determining the codes of right and wrong. Thomas Suddendorf and Michael Corballis explained that

humans can forecast the outcomes and choose to act now to secure future needs. Cultures have evolved complex moral systems that judge actions as right or wrong based on what the actor could or could not have reasonably foreseen to be the future consequences of the act. Law, education, religion, and many other fundamental aspects of human culture are deeply dependent on our ability to reconstruct past and imagine future events.
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Knowing a moral standard is of little use if one fails to monitor one's own behavior and compare it with the relevant standard. For this reason, a virtuous individual is also necessarily a self-aware individual. Large crowds of people can create a feeling of deindividuation or a loss of self-identity. Self-monitoring of behavior fades away as the individual melds with the larger group. If the group is inclined to destructive behavior, its actions can escalate out of control. Acts of violence, vandalism, and theft can erupt from a mob far more readily than from any one individual, with the exception perhaps of a psychopath. In a sense, a mob can become a psychopath. As another example, alcohol intoxication impairs self-awareness and “alcohol is well known to be implicated in a broad range of nonvirtuous behaviors ranging from interpersonal violence to sexual misdeeds.
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Finally, virtuous behavior depends on the self-control of impulsive thoughts and feelings. Transient feelings of anger or jealousy can, if acted upon, produce verbal or even physical violence. Having moral standards and being self-aware are by themselves insufficient without self-regulation. It is here that the concept of moral muscle makes good sense, for as with any muscle, fatigue can deplete one's capacity for moral conduct. Human beings are vulnerable to what Baumeister calls ego depletion.
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Tasks that require sustained attention and mental effort are depleting, just as is sustained physical exertion. Exercising self-control over impulsive thoughts and feelings is one of the tasks that takes mental effort and causes ego depletion. The executive function of inhibiting unwanted thoughts can fail as a result of mental fatigue. The mental work of constraining one impulse can make it harder to resist a
different, wholly unrelated impulse. Executive attention is a limited resource that can be overloaded, causing problems in self-regulation. As Baumeister puts it, “in all acts of volition the self uses some resource that operates like an energy or strength, and after such an act the self's stock of this resource is depleted.”
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After a hard day of work, it is especially difficult to regulate one's behavior and stick to goals. For the dieter, for example, the temptation of a large dinner or a high-calorie dessert is hard to resist after exerting self-control accomplishing tasks at work all day.

CRIMINAL RESPONSIBILITY

Roy Baumeister noted that the loss of self-control under ego depletion could account for lifestyles that characterize those repeatedly in trouble with the law. For example, most criminals are arrested repeatedly but for different crimes, contrary to the view of criminality as a specialized career choice (as movies like to portray it). Moreover, most criminals tend to show patterns that reflect poor self-control even in legal activities: “For example, criminals are more likely than others to smoke cigarettes, drink alcohol, be involved in unplanned pregnancies, and have erratic attendance records at school or work.”
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Does lack of capacity to self-regulate one's behavior imply a lesser degree of moral accountability for wrongdoing? The law has long recognized the criticality of
mens rea
, or guilty mind. If someone commits a crime without the capability of understanding the consequences of his or her actions, he or she lacks criminal intent and should not be punished to the same extent as one who does possess this capacity. Here is a clear and noble example of moral reasoning enshrined in the rule of law. Yet it is far less clear in what circumstances this principle applies.

In their article on
neurolaw, Annabelle Belcher and Walter Sinnott-Armstrong reviewed the facts of a notable case on criminal responsibility and brain research.
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In 1993, a seventeen-year-old male by the name of Simmons plotted, fully premeditated, to murder a woman named Shirley Crook. He brought with him two younger friends, Tessmer and Benjamin. His plan involved burglarizing the victim, followed by abduction and then murder to dispose of the evidence. She was bound, gagged, and thrown off a bridge in a
state park near St. Louis. She drowned that day in the waters of the Meramec River. Charged with first-degree murder, Simmons was convicted, not surprisingly given that he confessed to the murder and performed a videotaped reenactment at the crime scene. In addition, Tessmer testified against him, documenting his plotting of the crime and his bragging later about his deeds. Under Missouri law, the jury recommended a death sentence, and it was so imposed by the court.

For the next eleven years, appeals to the death penalty decision were upheld, but the decision was nevertheless brought before the US Supreme Court. Although all the elements of first-degree murder applied to Simmons's actions, and although Missouri law allowed for the death penalty in such a case, the Court heard the case because the defendant was not an adult at the time of the crime. In its 2005
Roper vs. Simmons
decision, the Court concluded that the immaturity of adolescents relative to adults reduced the murderer's criminal responsibility. Based on the Eighth and Fourteenth Amendments to the US Constitution, the Court ruled that capital punishment for crimes committed under the age of eighteen years, regardless of their heinous nature, was forbidden. Put differently, society has a moral responsibility to treat the actions of a seventeen year old differently than it treats the actions of an adult. With the 5–4 vote, the Court effectively changed the age of full responsibility for premeditated murder from sixteen to eighteen years of age.