The Neuroscience of Distributive Justice

Since the emergence of philosophical thought, an unresolved debate has persisted about a general definition of justice and equity. An aspect of that debate involves distributive justice, or how goods and benefits should be dispersed throughout a society in a fair and just manner. As an extreme example of this dilemma, imagine you are commissioned to deliver 100 lbs. of food to a famine-stricken region that consists of two villages a hundred miles apart. If you deliver half of the food to the first village, then travel to the second, 30 lbs. of the food will spoil during the trip. Would you deliver all of the food to the first village, or provide each village with only 35 lbs. of food in the pursuit of equity? What if you knew that 35 lbs. of food was not enough to fully alleviate the suffering of either village until the next shipment of food arrived?

Philosophers have offered several solutions to debates of this nature. Utilitarianism, a concept with ancient roots but most frequently associated with Jeremy Bentham and John Stuart Mill, asserts that one’s primary goal should be the achievement of a maximal amount of good or happiness. In the situation described above, a utilitarian might opt to deliver all of the food to the first village. This would maximize the sum of individual fulfillment, while the halving of the food would maintain a static level of suffering. Thus, delivering all of the food to the first village is the greater good.

Another approach to such a quandary is known as deontological ethics, which emphasizes not the consequences of one’s actions, but whether the actions are right or wrong, just or unjust. From a deontological perspective, it would be unjust to distribute the food unequally. A desire for some degree of fairness in all dealings seems to be a universal human trait, something deontologists point to in support of their doctrine.

Another question about distributive justice involves the extent to which emotion plays a role in the decisions it calls for. Many philosophers, both ancient and contemporary, assert that rational thinking is what allows us to make choices in difficult situations like the one above. Others argue that the processes behind those decisions cannot be devoid of an emotional influence, specifically one of an empathetic or sympathetic nature.

A study in this week’s Science examines distributive justice from a neural perspective, asking: what areas of the brain are active when we make such decisions? To find out, researchers used fMRI to scan the brains of 26 adults while they made decisions about allocating money to groups of children living in an orphanage in Uganda. During the allocations, the participants were forced to make a number of decisions that involved trade-offs between efficiency (analogous to Utilitarianism) and equity (deontology).

The investigators found that distinct neural regions are activated in the consideration of equity and efficiency. The putamen, a mid-brain structure that forms part of the dorsal striatum, seemed to be correlated specifically with efficiency. On the other hand, activity in the bilateral insular cortex was correlated with inequity. Regions of the caudate were activated by both. They also found that individual differences in aversion to inequity corresponded with higher neural activity in the insula.

Overall, the participants showed the greatest neural reaction to an inequitable distribution of food, leading the authors of the study to speculate that distributive decisions are made to avoid inequality more so than to engender efficiency. Thus, the results of this experiment seem to support the deontological argument. As the insular cortex is thought to play an important role in emotional processing, the experiment also indicates that our decisions are not devoid of an emotional element (contrary to the beliefs of Kant and Plato).

Thus, the imaging evidence from this study may help to explain why the debate over distributive justice has never been resolved. The concepts of equity and efficiency, and their respective values, are deeply rooted in our brains. Perhaps evolution never resulted in the disappearance of one or the other because they both are valuable in the decision-making process, depending on the situation. When all is said and done, though, it may be that the evolutionary value of fairness overrides that of efficiency.

Hsu, M., Anen, C., Quartz, S.R. (2008). The Right and the Good: Distributive Justice and Neural Encoding of Equity and Efficiency. Science, 320 (5879), 1092-1095. DOI:10.1126/science.1153651

Does Money Affect the Way You Think?

Money, perhaps more so than any other modern symbol, can elicit a vast array of emotions (depending to a large degree on its abundance in one’s life), including yearning, anxiety, pride, greed, envy, depression, and happiness. Of course there is not simply a direct correlation with money and any one of these emotional states, such as more money equaling more happiness or vice versa. In fact, past research has found that the effects money has on one’s well-being can be very disparate. On one hand, having more money may be good for your health and emotional state. On the other, people who place a high value on money have been found to have poorer social relationships than those who are more moderate in their view toward the attainment of wealth.

A group of researchers recently conducted a series of experiments to explore this paradoxical aspect of affluence. They formulated two hypotheses about the dual nature of money in the modern world. First, since money is the basis of most exchange in today’s society, they suggested that the thought of money should make people more focused on cost-benefit analyses and a market-pricing view of their environment. They thought that this perspective might encourage more emphasis on individual performance, since money is often correlated with the completion of personal tasks in our business-based economy. They predicted people with money on their mind would think of life in terms of inputs and outputs, with an awareness that greater input should result in a greater output.

They also hypothesized that the market mentality, while beneficial for personal performance, might hinder one’s ability to interact socially. Because it fosters a focus on individual performance, it might cause a decrease in sensitivity towards the needs of others.

To test their hypotheses, they used several different methods of exposing participants to money-related cues, while attempting to make the cues subtle enough that the subjects wouldn’t be aware of their presence. In one experiment, some participants sat at a desk with a screensaver that depicted money, while others saw screensavers of fish or flowers. In another, participants had to organize phrases that were or were not related to money, such as “I cashed a check” or “I wrote the letter”. Several other methods of exposure to money cues were used.

After being exposed to the cues, the participants were put in various social situations that tested their desire to be helpful, generous, sociable, or industrious. For example, to test willingness to help, a confederate would walk by and drop a handful of pencils (27 to be exact). Or, in another situation, a confused colleague would ask for assistance in understanding a task they were attempting to complete. Those who were exposed to money cues picked up fewer pencils, and those who weren’t spent 120% more time helping the confused colleague.

When given an opportunity to donate a portion of $2 the participants were given at the start of the study, those who had been reminded of money donated 39% of their payment, while those who hadn’t been donated 67%. They also, when allowed to situate the chairs in a room while waiting for another person to arrive, put more distance between their chair and the other person’s than the money-naïve group. When given a list of solo vs. group activities to take part in, the money-exposed group chose more individual activities than the control group (even when some activities included family members and friends).

With the choice of working on a task alone or getting help from a peer, the money-reminded participants chose to work alone, even though it meant doing more work. When faced with a challenging task, they spent 48% more time working at it before seeking help from the experimenter.

The researchers suggest these results may appear because a money-oriented person is focused on the inputs and outputs of the market, a view that tends to lead to an emphasis on individualization and self-sufficiency. They found no changes in emotion between the two groups, and thus assert that the differences in behavior are probably not due to a distrusting of others. Additionally, the fact that those who were reminded of money chose to persist on a task before asking for help indicates the results are not based purely on selfishness, as a selfish person would not have been so eager to do more work than necessary.

Regardless, the results do suggest that money can inspire an aversion to social interaction and a focus on the self. In modicum, however, this may be a necessary part of a capitalistic society, where one is forced to place an emphasis on ensuring they are treated equitably and compensated fairly for their work—and where they are forced to compete for their livelihood. An interesting follow-up to this experiment would be to use neuroimaging to see what is going on in the brains of participants when they make decisions after exposure to money cues, and how it is different from controls.


Vohs, K.D., Mead, N.L., Goode, M.R. (2008). Merely Activating the Concept of Money Changes Personal and Interpersonal Behavior. Current Directions in Psychological Science, 17(3), (in press).

Who's the Decider?

It’s too bad Benjamin Libet didn’t live another year. If he did he would have been able to see the first neuroimaging evidence to support what he found with an electroencephalogram (EEG) almost thirty years ago: what we consider our conscious decisions are preceded by unconscious neural activity, which seems to be the actual—as President Bush would say—decider.

Libet conducted his most influential experiment involving neural activity and conscious decision-making at the University of California, San Francisco, in 1979. While he measured their brain activity with EEG, he asked participants to carry out a simple motor task (like pressing a button) at their own volition during a period of time. How many times and when they completed the task was up to the participant, but Libet asked them to note exactly when they felt they had made the conscious decision to make the movement. He found there was significant stereotypical neural activity that preceded the conscious decision-making, indicating there may be unconscious processes at work in choosing to execute a motor task.

Libet’s study sparked a great deal of controversy, as some saw it as a denunciation of free will. And rightly so, as Libet himself suggested the only evidence in support of free will is our own assertion that it exists. His experiments appeared to show unconscious brain activity that preceded conscious choice, making the entire concept of “conscious choice” questionable.

A study published in Nature Neuroscience this week adds more ammo to the materialist’s belt. A group of researchers in Germany conducted a study very similar to Libet’s, but used functional MRI (fMRI) to measure brain activity instead of EEG. They analyzed the images with computer software developed to recognize specific patterns of neural activity, in this case those that anticipated the participants’ decisions to press the button.

Not only did the group find neural activity that preceded conscious choice, but using the computer programs they were able to predict what choice the participant would make—up to 7 seconds before they “decided” they had made it. The predictions were not perfect, but much better than chance.

The researchers assert that this study doesn’t exclude the existence of free will. Even Libet maintained that there was a role for consciousness in decision-making, not in initiating an act, but in the ability to suppress it. The authors of this study agree, indicating that the capacity to reverse a decision made by the unconscious brain—something they plan to investigate in the future—would support a type of free will.

Libet died in July of last year, unfortunately less than a year before current brain scanning technology caught up with his theories of the late 1970s.

Daisy, Daisy, Give Me Your Answer Do

Even the most successful attempts at artificial intelligence (AI) always seem to lack certain essential qualities of a living brain. It is a formidable task to create a robotic or computerized simulation of a human that seems to display original desires or beliefs, or one that truly understands the desires and beliefs of others in the way people can. This latter ability, often referred to as “theory of mind”, is considered an integral aspect of being human, and the extent to which it has developed in us may be one thing that sets us apart from other animals. Reproducing theory of mind in AI is difficult, but a semblance of it has been demonstrated before with physical robots (click here for an example). Until now, however, it has never been recreated in computer generated characters.

A group of researchers at Rensselaer Polytechnic Institute (RPI) have developed a character in the popular computer game Second Life who uses reasoning to determine what another character in the game is thinking. The character was created with a logic-based programming RPI calls RASCALS (Rensselaer Advanced Synthetic Character Architecture for “Living” Systems). The program involves several levels of cognition, simple systems for low and mid-level cognition (like perception and movement), and advanced logical systems for abstract thought. The group believes they can eventually use RASCALS to create characters in Second Life that possess all the qualities of a real person, such as the capacity to lie, believe, remember, or be manipulative.

Second Life is a life-simulating game, similar in some ways to the popular game The Sims. Unlike the The Sims, however, Second Life involves a virtual universe (metaverse) where people can interact with one another in real-time through avatars they create for use in the game.

The character created by the group at RPI, Edd, appears to have reasoning abilities equivalent to those of about a four-year old child. To test these abilities, Edd was placed in a situation with two other characters (we’ll call them John and Mike). Mike places a gun in briefcase A in full sight of John and Edd. He then asks John to leave the room. Once he is gone, Mike moves the gun to case B, then calls John back. Mike asks Edd which case John will look in for the gun.

Does this sound familiar? It's an actual psychological test developed in the 1980s, originally known as the Sally-Anne test. The Sally-Anne test plays out the same scenario described above, only with dolls and a marble or ball (since its inception the test has been done with human actors as well). A child watches the Anne doll take a marble from Sally’s basket and put it in her box while Sally is not in the room. If the child, after watching the interaction, can guess when Sally returns that she will look in her basket for the marble, it demonstrates he or she has begun to form theory of mind. The child is able to understand that other people have thoughts and beliefs different from his or her own. They realize that when Sally re-enters the room she is unaware the marble has changed positions, so she will look in the spot where the marble originally was. The ability to make these types of attributions of belief usually develops at around age three to four in children.

Edd, the character from Second Life, is able to do the same. When Mike asks him in which case John will look for the gun, he will say case A—the case John saw the gun placed in (for the demonstration click here). And Edd is not programmed specifically to make this choice. Instead he “learns” from past mistakes that, if John cannot see the gun being moved he will not know it is in the other briefcase.

The research group at RPI see Edd as a first step in the creation of avatars on Second Life that can interact with humans in a manner unlike that of any simulated characters before, being able to understand and predict the actions of others, and act virtually autonomously. They see potential benefits of this technology in education and defense, as well as entertainment. IBM, a supporter of the research, has visions of creating holographic characters for games like Second Life, which could interact with humans directly.

This is all pretty amazing stuff, but for some reason HAL singing “Daisy Bell” keeps eerily replaying in my head as I write it.

Genes and Happiness, or Free Will Revisited

As I begin writing this post I can’t help but be reminded of the one I wrote a few weeks ago about the troubles one runs into when trying to reconcile present-day understandings of neuroscience and genetics with the traditional concept of free will. A team of researchers from the University of Edinburgh and the Queensland Institute of Medical Research recently conducted a study to investigate how much our subjective sense of happiness is dependent upon our genetic makeup (and thus personality style). Is our ability to be happy solely up to us ("us" being defined as hypothetical beings with complete free will), or is it constrained by the type of person we are, which is determined to a large extent by our genes?

To find out, the researchers studied a sample of 973 pairs of twins (365 monozygotic, or identical, and 608 dizygotic, or fraternal). Twin studies are an experimental method used in behavioral genetics to isolate the influence of genes on personality. Since monozygotic twins share 100% of their genes, behavior that is based primarily on genetic makeup can be assumed to be seen in both members of a pair. The actual observations can be compared with the phenotype of dizygotic twins, who only share about 50% of their genetic information. Similarities between monozygotic twins that aren’t as significant in the dizygotic twins can be assumed to have a prominent genetic basis. In this model, environmental effects are also considered, but the composition of the sample allows the effects of gene and environment to more easily be separated.

The researchers used a questionnaire called the Midlife Development Inventory (MIDI) to assess the personality of the participants. The scores were averaged across five dimensions that describe overall personality characteristics, known as the Five Factor Model (FFM). It consists of Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism. The FFM is a personality assessment tool that was developed in the early twentieth century. It has been refined numerous times, and been shown to be a reasonably accurate instrument for making generalized appraisals of personality.

Certain traits measured by the FFM have also been correlated with one’s sense of subjective well-being, especially Neuroticism, Extraversion, and Conscientiousness. The reasons why exactly are uncertain, and could be due to any number of factors involving how these traits affect one’s social interactions and lifestyle. For example, low Neuroticism may indicate emotional stability and Conscientiousness could denote self-restraint, both qualities which are often considered important in leading a contented life.

The researchers also conducted an interview to assess well-being, asking participants how satisfied they were with their life at present, how much control they felt they had over their lives, and how satisfied they were with life overall.

The group found that, as has been seen in the past, subjective well-being was correlated with the personality traits of the FFM. Specifically, it was negatively correlated with Neuroticism, and positively correlated with Extraversion, Openness to Experience, Agreeableness, and Conscientiousness. In addition, the correlation between the FFM characteristics in monozygotic twins was significantly higher than in dizygotic twins, suggesting a genetic basis for the formation of these personality traits.

Subjective well-being was shared between the twins at a level correlated with that of their positive personality traits. What this suggests is the following: we are born with a particular genetic makeup that is deeply ingrained and difficult to change, regardless of experience. This makeup is translated into personality traits that can be broadly generalized into categories such as neurotic, extroverted, etc. Some of these traits end up being conducive to our happiness and well-being. The less neurotic an individual is, for example, the happier he or she tends to be. Since these attributes are genetically prescribed and predictive of our happiness, some would say the amount of happiness we are able to experience in life is limited to a great extent by our genetic makeup.

It is easy, however, to take this argument a bit too far. A headline today on, for example is “Genes Hold the Key To How Happy We Are, Scientists Say." This is not really what the authors of this study are claiming. They instead are suggesting our genes provide us with a starting point, a set-point of emotional stability, which we end up moving from in one direction or another based on our experiences. While it is important for some of us to understand how the limitations of our genetic makeup might handicap us when it comes to the enjoyment of life, it’s also necessary to point out that the environment can have drastic effects on who we are compared to our original constitutional makeup. People born with what might be considered an unfavorable personality assessment according to the FFM often come up with innovative ways to improve their life, and their outlook on it. So, do genes alone hold the key to how happy we are? I don’t believe so. But they may provide us with a rough outline, albeit one that we are able to constantly revise throughout our lives.

Of course, I may just be in a good mood today. I don’t think the post I wrote about neuroscience and free will a few weeks ago was so optimistic. Those revisions we make in that outline may themselves be constrained by genetic limitations on the options we are able to imagine…and the argument can go on and on…

Weiss, A., Bates, T.C., Luciano, M. (2008). Happiness Is a Personal(ity) Thing: The Genetics of Personality and Well-Being in a Representative Sample. Psychological Science, 19(3), 205-210. DOI:10.1111/j.1467-9280.2008.02068.x