Finding a genetic footprint in the predisposition to trust and cooperate leads to a somewhat uncomfortable question. What chemical, hormonal and neuronal states make a person more predisposed to trust others? As with olfactory preferences, a natural starting point for studying the chemistry of cooperation is examining what happens in other animals. And a likely chemical candidate emerges: oxytocin, a hormone that modulates brain activity and plays a key role in the predisposition to social bonding. A player who inhales oxytocin plays the trust game much more generously than a player who inhales a placebo.
Oxytocin is involved in parenting behaviour. In fact, it plays a primary role in the process of activating the uterus during childbirth, which explains its etymology: from the Greek, oxys, which means ‘quick’, and tokos, ‘birth’. It is also released by sucking on the nipple, which facilitates nursing. But oxytocin not only predisposes the body for motherhood: it also prepares mothers’ characters for the huge feat they are about to undertake. Virgin sheep, when receiving oxytocin, behave maternally with the lambs of others as if they were their own. They become great mothers. And vice versa, mother sheep, when given antagonistic substances that block the action of oxytocin, lose their typical maternal behaviours and neglect their offspring. So oxytocin was established as the molecule of maternal love and, more generically, of all love.
Since then a large body of research has shown in one experiment after another that administering a single dose of oxytocin improved different aspects of social cognition: trust, emotional recognition, the ability to direct and sustain gaze at others, understanding, cooperating, and reasoning about high-level social interactions. Oxytocin emerged in the media, with some reason, as the holy grail for empathy, social interactions, emotions and love. Could we simply irrigate oxytocin and make our world a better one? Would dreams of peace, trust, bonding, and a more just and caring society be solved by increasing the dose of a hormone?
The oxytocin hype was fuelled even more when genetics came in to show that variations of the OXTR gene that encodes the receptor of oxytocin were linked to deficits in social behaviour. This was shown directly in animal models, where this gene can be manipulated, but it was also found that variations in this gene could increase the risk of autism.
This closed the loop. Impaired social interaction is a diagnostic hallmark of Autism Spectrum Disorders. Autism has a very high prevalence (estimated to 1 in every 68 individuals) and there is currently no satisfactory (or even close to satisfactory) medical treatment, despite the enormous effort that has been devoted to it. In the light of this, oxytocin offered huge promise to a population that was avid for solutions. The first studies showed that, as with normal adults, single doses of oxytocin could increase social cognition of autistic children. But numbers matter. The effect was quite modest: children’s performance in a task in which they had to infer the emotion of another person by looking at their eyes improved, on average, by from 45 to 49 per cent. This is still very far from people without autism, who on average perform in the same task at above 70 per cent.
Oxytocin worked, but the effect was very small, almost negligible. And there were more important reasons to temper the oxytocin hype. Most drugs behave very differently when used in a single dose compared to extended treatments of multiple doses. And, here, results from animal research were not so promising. The same drug that after being administered boosted social behaviour in mice, sheep and voles resulted in very weird social behaviour in the long term, especially after repeated exposures. And, indeed, ten years of research have not shown any consistent effect of sustained treatments of oxytocin to improve social deficits in autistic children. Adam Guastella, one of the world leaders in oxytocin investigation, published in 2016 a review paper which analyses all current evidence to conclude that repeated doses of oxytocin have very limited therapeutic potential.
Let’s put all this together, because that gives us an important lesson not only on oxytocin and social cognition, but more generally on how naive interpretations of neuroscientific findings may be strongly misleading. It is true that oxytocin plays a role in social behaviour–there is ample evidence to support this idea. Oxytocin is expressed in nature during motherhood (a moment of maximal social bond), removing oxytocin usually leads to different forms of social neglect and lack of trust, and, conversely, providing oxytocin leads to increased trust, empathy, emotional recognition and understanding… Hacking the genes of oxytocin receptors leads to animals with very weird social patterns, and people who have atypical variations of these genes are more likely to express autism or other diseases which affect social behaviour. So evidence spans genes, molecules, pathology, and laboratory psychological experiments on humans and animals in a consistent picture. However, the fact that a molecule plays a role in this process does not imply that simply consistently boosting this molecule will lead to increasing this behaviour. However, this is often hidden or unsaid in the broad media reports of these studies, mainly following the natural desire to make a story simple, often more beautiful and optimistic than it really is.
Oxytocin is a biological and chemical trail that lays the foundations which predispose a person to cooperate, but it is a huge and unfounded leap to assume that this implies that a network of trust, love and social understanding can be built by popping a pill.
The seeds of corruption
Trust is the foundation of human society. On every scale, in every stratum, trust is the glue of institutions. It is the key to friendship and love, and the basis of commerce and politics. When there is no trust, the bridges connecting people break, and societies fall apart. Everything collapses. And this idea of everything breaking apart is expressed in Latin as con (everything) and rumpere (to break), which is where we get the word corrupt. Corruption leaves nothing intact.* It destroys the fabric of society.
The world map of corruption is not hard to imagine.** The Nordic countries, Canada and Australia, are pale yellow, indicating a very low perceived level of corruption. Europe shows a gradient with corruption increasing from north to south and from west to east. The United States and Japan have intermediate orange values, and Russia and most of Asia, Africa and South America (with the notable exception of Chile and Uruguay) show up as the places in the world with the highest level of corruption.
Many economists think that endogenous, structural corruption, which is filtered through all the pores of a society, is a fundamental obstacle to development. Therefore understanding why there are very different corruption perception values is pertinent, especially when analysing how this mechanism can offer clues that might eventually change the course of things.
Rafael Di Tella, an economist, Argentinian Olympic fencer and Harvard professor, developed–along with his doctoral student Ricardo Pérez-Truglia–a modest project within this larger objective, which sought to detect one of the seeds of corruption. Rafael’s premise begins with a quote from Molière: ‘He who wants to kill his dog, accuses it of rabies.’ What he implies is that the perpetrator of a wrong action gets away with it by assigning the blame to the victim.
From a normative perspective we should construct opinions about others based on what they have or have not done; yet we do so based on the shape of their face, the structure of their speech or the way they walk. The consequences of Molière’s conjecture are even more unsettling. It implies that we construct unfounded opinions about others to justify our aggression.
Rafael took Molière’s idea to the laboratory with an ingenious experiment called the ‘Corruption Game’.
Like all games derived from the ‘Dictator Game’, it begins with a player–the agent–who decides how to allocate twenty tokens, which were the payment for a boring job that was done by the agent and another player (the allocator), who never meet throughout the experiment. The fundamental aspects of the Corruption Game are as follows:
Some agents can choose, completely freely, how many tokens they want to keep. Others have a small margin of action: they can only choose to kee
p ten, eleven or twelve tokens. According to the rules of this version of the game they are forced to distribute at least eight to the other player. This controls how much the agent can mistreat the other player, so as to see later what the agent thinks about the recipient.
The recipient receives the tokens in sealed envelopes, without knowing how they were distributed, then can trade those tokens and the agent’s tokens for cash. When doing so the recipient has to make a decision: trade them fairly–five dollars for each token–or trade them corruptly according to the arrangement offered to the cashier, who will pay $2.50 for each token but in exchange will offer a bribe. So the arrangement benefits the cashier and the recipient, and cheats the agent.
In this game, the agent can act in a generous or selfish way, and the recipient can act in an honest or corrupt way. The question (Molière’s) is whether the selfish agents justify their action by arguing that their recipients were going to be corrupt. The fundamental key is that the tokens are in a sealed envelope and therefore, when deciding to trade them, the recipient still doesn’t know how they were distributed. In this game, the player who acts corruptly does so on the basis only of personal predisposition, not for revenge or payback.
Despite that, Molière governs the game. Those agents who were offered more freedom to play aggressively tend to deem the recipients as more corrupt. And this is true both in terms of their fellow players–whom they haven’t met–and their view of the general public. When we can choose to be more hostile and aggressive, we tend to think that others are corrupt. Then, all dogs are rabid.
It remained to be seen how this plot is perpetuated; how opinions emanating from our own actions can, in turn, condition what we do, leading to a domino effect of corruption in the social network. In order to find this out, Andrés Babino, a doctoral student in my lab, and I joined the team Rafael Di Tella had put together.
The key was observing how the agent acted according to the opinion they had of the other player. We created a new experiment in which the recipient had to act according to one of these three instructions: The recipient:
(1) is forced to trade each token for its face value;
(2) can choose to act corruptly or not;
(3) is forced to trade the tokens for half of their value and keep the commission–in other words, is forced to act corruptly.
It could be expected that the agent–who knew which of the three rules the other was bound by–would distribute more when knowing that the recipient would not act corruptly, slightly less when uncertain whether the other player would act corruptly, and even less when warned that the recipient was forced to act corruptly.
However, that was not what happened. In fact, the agent distributed tokens with equal generosity when knowing that the recipient had no freedom of choice. It didn’t matter whether the way the recipient traded turned out to be more or less favourable for the agent. And the agent was much less generous when unsure as to what the recipient would do. In the game of beliefs and trust, it is ambiguity that’s the real killer.
The same argument can be applied in the opposite way. We are hostile with those we believe could betray us. It is the fear of being made a fool of, of trusting someone who will not reward us in the same way. So, putting together the two pieces of the puzzle, our own selfish actions turn into harmful beliefs about others (‘everyone is corrupt’), and ambiguity about others’ beliefs (‘they may be corrupt’) makes us selfish and aggressive. It is a vicious circle that is only remedied by firmly sowing certainty and trust. And this, at least in the laboratory, is possible. In order to do so we must enter the deepest recesses of words and the deepest structures of the brain.
The persistence of social trust
When players make a confident, cooperative and altruistic decision in the trust game, the regions of their brain that codify dopaminergic circuits of pleasure and reward are activated. In other words, our brains react similarly when exposed to something pleasurable–sex, chocolate, money–as when displaying solidarity. Being good has value. And that explains why in all the economic games we rarely see decisions that exclusively maximize financial profit and ignore all social considerations. It turns out that there is a foundation for this hypothesis. Social capital is not only lovely and honourable–it pays.
When playing the trust game repeatedly, players learn and align in a pattern: if one player distributes generously, the other becomes progressively more generous. And the opposite is also true, if one is not generous, the other distributes in an increasingly more selfish manner. In general, the game comes to two solutions; the perfectly cooperative, in which all players win more, and the selfish, in which the first player wins less and the second gets nothing. The brain discovers the other player’s inclinations using the same learning mechanism that explains the neuroscience of optimism. A person, before playing, already has an expectation of their fellow player, whether that player will cooperate or not. When they find a discrepancy, the brain’s caudate nucleus activates and releases dopamine.
This produces a signal of prediction error that in turn makes us learn to calculate more precisely whether the other player will cooperate in the future. As this calculation becomes more exact, we learn to know our neighbours. As such there is less of a discrepancy between what is expected and what is found, and the dopaminergic signal lessens. It is the neuronal circuit of social reputation.
What’s most interesting here is understanding how this slow cooking of trust thickens into an obstinate tendency to trust others. This can perhaps explain in part the idiosyncratic differences between Argentinians, Chileans, Venezuelans and Uruguayans in their predisposition to trust others or, alternatively, to become corrupt.
The key experiment was done by a neurobiologist, Elizabeth Phelps, in New York. A person repeatedly plays trust games with different players. Each of them had previously been described in a brief made-up biography that marked them as morally upstanding or immoral.
And she discovered something extraordinary in the brains of those playing with someone described as morally upstanding who nonetheless behaves selfishly. Since the brain learns from discrepancies, we would expect that a prediction error would be produced in the caudate nucleus, releasing dopamine and in turn allowing for a revision in the opinion of the other person. Their good reputation would have to be adjusted to take into account the bad action just observed. But that doesn’t happen. The brain turns a blind eye when there is a discrepancy between your moral expectation of a person and their actions. The caudate nucleus does not activate, the dopamine circuits shut off and there is no learning. This obstinacy is a lasting social capital that can resist certain setbacks. Those who establish (based on the biography they were given) that the other player will act morally do not change that belief merely because they find an exception. Which is to say, the trust network is robust and sturdy. The seed of social confidence is optimism’s first cousin.
We can recognize this in a more mundane situation; for example, when someone whose taste in movies we respect enthusiastically recommends a film that we think is without merit. We curse their name in the moment, but our trust in them persists. There would have to be many more failed recommendations before we began to question their judgement in recommending films to see. Yet if a person we barely know recommends a bad book to us, we will be unlikely to take their advice ever again.
To sum up…
Over the course of this chapter we have travelled far and wide through human decision-making, from our simplest choices to our most sophisticated and profound. The decisions that define our morality, our notion of what is fair, whom we love. Those ones that José Saramago says ‘make us’.
Over the course of this journey a latent and implicit tension naturally appeared. On one hand, we spoke of the existence of a common neuronal circuit that mediates practically every human decision. On the other, we have shown that our ways of deciding are markedly personal, and that our decisions define us. Some are utilitarian and pragmatic; some
are trusting and willing to take risks; others are prudent and spineless. What’s more, this mishmash of decisions coexists deep within each of us. How is it possible that one single cerebral mechanism can produce such a wide range of decisions? The key is that the machine has various screws, and the way they are tightened can result in decisions that seem very different despite having structural similarities. So a slight change in the balance between the lateral frontal cortex and the medial frontal cortex defines us as cold and calculating, or emotional and hypersensitive. Often what we perceive as opposing decisions are, in actuality, only a very slight disturbance in a single mechanism.
This is not only true of the decision-making machinery. It turns out to be perhaps the essence of the biology that defines us: diversity within regularity. Noam Chomsky caused a stir when he explained that all languages, each with its own history, idiosyncrasies, usage and customs, share a common skeleton. This holds true for the language of genetics. We all roughly share the same genes; otherwise it would be impossible to talk about a ‘human genome’. But the genes are not identical. For example, there are certain places on the genome–called polymorphisms–that are wildly varied and, to a large extent, define the unique individuals we each are.
Of course, these seeds take shape within a social and cultural breeding ground. Despite a genetic predisposition to and a biological seed for cooperation, it would be absurd from every standpoint to believe that Norwegians are less corrupt than Argentinians because of a different biological makeup. However, here there is an important nuance. It is not impossible–in fact, it’s quite likely–that the brain’s shape and organization develop differently depending on whether it’s reared in a culture based on trust or distrust. It is within cultures that the machine’s screws are tightened, its parameters are configured, and the results are expressed in how we make decisions and how we trust. In other words, culture and brain are intertwined in an eternal golden braid.*
The Secret Life of the Mind Page 10