Measuring Responsibility

Moral Agency and the Brain

by Christina M. H. Powell

Teaching parishioners to take responsibility for their actions and make God-pleasing decisions comprises a key part of a pastor’s role. A Christian understanding of morality hinges on the belief that each person facing temptation has the freedom to choose to obey God, and God will hold him accountable for his moral choices. As Paul explained in a letter to the Corinthians, “For we must all appear before the judgment seat of Christ, so that each of us may receive what is due us for the things done while in the body, whether good or bad” (2 Corinthians 5:10).

Our understanding of our moral agency, or ability to make moral judgments and act accordingly, connects to our sense of guilt for wrongdoing as well as our sense of pride in our achievements. Research studies show that people who read a statement reinforcing belief in free will cheat less on a subsequent test than those who read statements encouraging a belief in determinism (portraying behavior as the consequence of environmental and genetic factors). These studies suggest that debates over free will versus determinism may have practical implications for a person’s behavior.1

Forefront neuroscience research seeks to explore the neural basis of moral agency, looking for brain functions that influence our decision-making ability. Researchers often gain insights by studying diseases and injuries. For example, studies of rare neurological disorders, such as alien hand syndrome, help researchers understand the relationship between agency and purposeful limb movement. Research conclusions lead to more than just philosophical debates. Examining the biological basis for our actions can change how and why we hold people responsible for their moral decisions.

A Biological Basis for Decisions

Moral decision making has a clear biological basis. When people feel guilt, compassion, or embarrassment, certain regions of the brain become activated, specifically the anterior and medial prefrontal cortex and the superior temporal sulcus. Empathic emotions, such as guilt and compassion, recruit the mesolimbic pathway as well. Indignation and disgust activate the amygdala. Reflecting on a moral decision involves a large network within the brain.2 Of course, as Jesus told the Pharisees, “For the mouth speaks what the heart is full of. A good man brings good things out of the good stored up in him, and an evil man brings evil things out of the evil stored up in him” (Matthew 12:34,35). As fully integrated beings, we should expect that our brains must process our moral choices.

A potential conflict between how we view our freedom to make moral decisions and current neuroscience research surfaces in experiments that measure our awareness of decision making. Neuroscience experiments performed since the 1980s demonstrate that the brain makes a subconscious decision before becoming consciously aware of the choice. For example, the same electrical brain wave changes shown to precede all limb movements occur hundreds of milliseconds before a person consciously decides to move a limb. One interpretation of these results is that our brains decide our choices in advance, making our freedom to choose our behavior an illusion.

A closer look at these experiments, which involve simple actions such as pushing a button, opens up the possibility of alternative interpretations. The experiments measure the subjective feeling of having an impulse to move, rather than the process of deliberating a decision that would require higher cognitive function. Additionally, the experiments do not rule out the concept of a “free won’t” or the ability to consciously override our subconscious impulses.

Perhaps on a more philosophical level, our imagination, defined as our ability to make models of future scenarios and potential consequences of our actions implies that we are capable of choices. The predictability of our brain functions permits us to act reliably as moral agents. Some philosophers propose that like the wave-particle duality found in quantum mechanics, free will and determinacy will remain a paradox of the biological sciences.

When One Hand Knows Not

Jesus instructed His disciples to “do not let your left hand know what your right hand is doing” when they gave to the poor so their reward would come from their Heavenly Father and not from men (Matthew 6:3). For a person suffering from the rare medical condition known as Alien Hand Syndrome (AHS), having a left hand that knows not what the right hand is doing, is a daily reality. The condition, first identified in 1908, involves a hand behaving as if it had a will of its own distinct from the desires of the person. A person with AHS can feel normal sensation in the hand, but he loses a sense of agency in the limb. The patient cannot voluntarily control the hand, yet the hand makes purposeful movements.

For example, a person may turn on a light switch with his right hand by choice, then find that his left hand turns the light back off. When a patient attempts to feed himself, his left hand may try to prevent the right hand from bringing the spoon to his mouth. The rare condition interests researchers because a person’s sense of agency has been disconnected from the purposeful movement of the limb. Doctors have documented most cases of AHS in people who have had the two hemispheres of their brain surgically separated in a procedure used to relieve the symptoms of extreme cases of epilepsy. AHS also occurs in patients who have experienced brain injury from a stroke, head trauma, tumor, or infection.

Some psychologists cite AHS as evidence that there is a part of the brain that gives a person the sense of having a free will over his behavior. Thus, these psychologists contend that our brains simply created the illusion of free will, which the brain disrupts for the patient experiencing AHS. However, as William P. Cheshire, Jr., professor of neurology at the Mayo Clinic in Florida, points out, “If free will is ultimately a delusion and human decisions are reducible to the blind product of material efficient causes, then there could be no reason to argue that one ought to choose to act in a certain way instead of another. … It would make no sense to appeal to reason as a guide to decisions if all thought ultimately reduces to the irresistible consequence of material causes prodding us as inexorably as lines of computer code.”3 He feels that if free will truly exists, we should expect to find an area of the brain that processes our sense of agency. He considers the acquired inability to perceive alien hand behavior as similar to patients who, though able to hear, lose the ability to recognize the rhythm and harmony of sounds, a condition known as receptive amusia (musical deafness). Just as musical deafness does not prove that a symphony is an illusion, the loss of a sense of agency for a left hand does not prove that free will does not exist.

Ethical Implications

Neuroscience research that measures a person’s responsibility for his or her actions has everyday ethical implications. Our understanding of brain development may change how we punish juvenile offenders. In specific cases, we may discover that a suspected criminal was not responsible for his behavior because a brain tumor impeded a crucial mental function.

Beyond applications in the justice system, neuroscience research may improve our ability to predict behavior. If we find that changes in certain brain structures predict antisocial behavior, what should we do with that information? Should we screen for propensity to violent behavior? Like genetic testing, such screening raises issues related to confidentiality, invasion of privacy, and failure to consider the environmental factors that may render such predictions meaningless.

In exploring the biological basis for moral agency, we must be cautious that we do not medicalize away personal responsibility, redefining sin as simply a disease state. As Joshua told the Children of Israel, “Choose for yourselves this day whom you will serve” (Joshua 24:15). That choice is still before us, and every pastor must remind his or her flock of the importance of this decision.


1. Kathleen D. Vohs and Jonathan W. Schooler. “The Value of Believing in Free Will.” Psychological Science. 2008;19(1):49–54. Available at Accessed 19 January 2012.

2. Jorge Moll, Ricardo De Oliveira-Souza, Griselda J Garrido, Ivanei E Bramati, Egas M.A. Caparelli-Daquer, Mirella L.M.F. Paiva, Roland Zahn, Jordan Grafman, “The Self as a Moral Agent: Linking the Neural Bases of Social Agency and Moral Sensitivity.” Soc. Neurosci. 2007; 2(3,4):336–52.

3. William P. Cheshire, “Does Alien Hand Syndrome Refute Free Will?” Ethics in Medicine: An International Journal of Bioethics. 2010;26(2):71–76. Available at: Accessed 19 January 2012.