Decision Making: Biology, Free-Will and Accountability

The concept of decision making, has been a central focus of intellectual pursuit since the dawn of man. Previously a philosophical and theological discussion, in recent years this task has been taken up by neuroscientists and biological psychologists. This blog entry will consist of two sections. The first is a brief overview of some of the evidence linking biology and decision making. The second is a discussion of moral accountability in light of biology.
Part I: Biology and Decision Making

In part I, I will present a range of evidence that converge upon the claim that brain function dramatically influences decision making.

Evidence from brain injury

One of the most discussed case studies in psychology is the case of Phineas Gage, a railway worker who miraculously survived a terrifying incident in which a railroad spike pierced his skull from cheek to crown. Despite the massive brain damage, Gage quickly recovered his faculties and appeared to be normal with one exception. His personality was unrecognizable. A previously calm and serene man, Gage was now irritable, impulsive, and rageful.  He was, quite simply, no longer Phineas Gage. While this represents an extreme case, the general principle has been observed for decades. People’s personalities change, sometimes dramatically, as a result of brain injury. They will often make decisions that they never would have before the injury. Undeniably then, brain structure and function is integral for the emergence of personality and decision making.

Evidence from pharmacology

Research with psychoactive drugs has shown that decision making and personality can be altered by pharmacology. Medications can make people more or less impulsive; they can help people concentrate or make them exceedingly distractible; they can make people calm or induce severe panic just to name a few. In fact there are few aspects of personality that cannot be altered by medication. Without getting too mired in biochemistry, all one really needs to know in order to see that brain function gives rise to behavior is that all psychoactive drugs impact neuronal activity in brain and critically all drugs that do not, are not psychoactive. The fact that drugs influence decision making suggests that brain biology is intimately tied with decision making and consciousness.

Evidence from genetics

The field of behavioral genetics is full of findings linking specific behaviors with genetic markers. It would take literally weeks to discuss every type of behavior that has been linked with genetics so instead I will provide a brief list: neuroticism, extraversion, impulsiveness, worry, riskiness, drug use, intelligence, promiscuity, attraction, mental illness, athleticism, etc. One’s genetic hand is clearly dealt long before any decision making ability, so the causal link is generally obvious. While the story is not as simple as “you have gene X therefore you will do behavior Y,” the general theme is clear. Genetics strongly influences behavior in nearly every facet of our lives, and these factors precede subjectivity.

Addiction as exemplar

Addiction can be conceptualized as a disorder of decision making. Specifically, addiction is the result of the extremely rewarding nature of certain drugs in conjunction with dysregulated executive decision making faculties. First, dopamine neurons in the mesolimbic brain areas encode reward, and all drugs of abuse stimulate activity in this area. In fact, the ability for a drug to be addictive is directly related to the ability of that drug to stimulate dopamine release in these areas. Secondly, frontal regions of the brain, which are linked to regulatory control become atrophied by frequent drug use. Thus the addict’s ability to regulate behavior is diminished. The combination of disproportionately high reward from drugs and reduced executive control gives rise to a situation where the addict is driven to use drugs despite serious and persistent consequences. If there is a clearer example of biologically induced dysregulated decision making, I have not heard it. Addiction is a case where pharmacology, neuroadaptation, genetics and, at times, brain injury, all come together to create serious and costly decision making deficits.

Evidence from direct observation

Neuroscientists have begun to peer into the brain while it makes decisions. One particularly poignant paper analyzed brain activation using functional Magnetic Resonance Imaging to predict participants freely chosen decisions[1]. In their own words: “We found that the outcome of a decision can be encoded in brain activity of prefrontal and parietal cortex up to 10 s before it enters awareness. “ Not only was brain activation indicative of the decision being made, but the neural activity predicted outcomes well before the participants were even aware they were making a decision in the first place. If studies of this nature are replicated  [which recent reports have done 2, 3, 4], there appears to be little doubt that subconscious, biologically determined brain activity gives rise to decision making in a predictable and testable way. Interestingly, one follow-up study found modest predictive utility of purely random activity prior to stimulus presentation [3]. While some may be tempted to say this is evidence against a deterministic account (i.e. Deepak Chopra), it is important to clarify that, when people discuss free will, they are certainly not talking about the influence of true randomness such as quantum mechanics or even organic chemistry would suggest. A purely random factor is no more conducive to freedom on the part of a conscious agent as determinism because the influence of randomness is still being imposed upon the agent, as opposed to coming from agency itself.

Part II Free-will  and accountability

Thus far, I hope I have made it clear that biology has significant influence over the decisions we all make. The issue then arises, if our decisions are indeed predetermined by our biology, how do we hold people accountable for the decisions they make? In this second section I will pursue two independent justifications for moral accountability in the context of deterministic psychology.

Argument from utility

The first and simpler argument is that holding people accountable has utility for a society. Accountability can be useful in a myriad of ways ranging from separating trouble-makers from the general population to restoring social balance. The most applicable way though, deals with how humans actually make decisions. While it is clear that we are far from perfect at weighing costs and benefits, people do consider the consequences of their actions before proceeding, thus the threat of punishment can and does shape behavior. In this way, establishing laws and holding people to them makes for a better society for everyone.

Argument from cognitive capacity

Before getting to the meat of the argument, I must address a common misconception with deterministic psychology about what is actually being held accountable. Countless times I have heard “you can’t hold person X responsible if their biology made them do it”. The misconception is that this statement supposes a person X that is categorically separable from his or her brain. As I have argued, the self is an emergent property of the brain. Thus when we say we are holding person X accountable for their actions we are in reality holding their brain accountable for what their brain did. With that established, we can look at the role of cognitive capacity.

Everyone reading this knows what it is like to make a decision. The reflective consciousness that goes into making decisions is a thing of beauty (a beauty which is not necessarily tarnished by scientific explanation, just as the beauty of a sunset is not tarnished by astronomy or ophthalmology). An essential component of human consciousness is the ability to consider a projected hypothetical future. A boulder, virus, lion, and even infant, are not held responsible because they are not capable of considering consequences. Normally developed adults are, and it is this capacity for consequentialist thinking that allows us to hold people morally accountable. When we say person X is morally accountable, essentially what we are doing is holding person X’s regulatory control responsible for not being persuaded by potential consequences. Ask yourself, if someone had zero ability to regulate instinctual behavior, would you hold them morally accountable for their actions? Our legal system certainly doesn’t. Yes, regulatory control is subject to biological influence, but saying that does not change the subjective experience of making a choice. If person X consciously considered the consequences and was not dissuaded by them, then he can and should be held accountable, whether or not deterministic biology influenced his decision.

Free will only contributes the possibility that an alternative decision could have been made. However, this is clearly not the source of moral accountability, as a random number generator would not be held accountable if hooked up to a missile silo. Additionally, I have already pointed out that life forms without reflective consciousness are not morally accountable and there is clearly variability in their actions. Thus I propose that multiple possible decisions, as suggested by free will, are not sufficient for moral accountability, and given the importance of reflective thought, are neither sufficient nor necessary.


1.            Soon, C.S., et al., Unconscious determinants of free decisions in the human brain. Nature neuroscience, 2008. 11(5): p. 543-5.

2.            Bode, S., et al., Tracking the unconscious generation of free decisions using ultra-high field fMRI. PloS one, 2011. 6(6): p. e21612.

3.            Rolls, E.T. and G. Deco, Prediction of Decisions from Noise in the Brain before the Evidence is Provided. Frontiers in neuroscience, 2011. 5: p. 33.

4.            Falk, E.B., et al., Predicting persuasion-induced behavior change from the brain. The Journal of neuroscience : the official journal of the Society for Neuroscience, 2010. 30(25): p. 8421-4.