We are a cooperative species. We dominate the entire planet thanks to our abilities to cooperate and that's, very puzzling because we're also very selfish. So why do we cooperate? We're a social species? We have lived in groups for at least half a million years during which we became more and more dependent on one another.
And when we interact, we realize we could attain something greater when we collaborate. But at the same time, we experience this tension between what's good for me and what's good for. All of us, take for example, doing chores at home, I liked it better when the others take care of that when I save my energy for something more interesting. But if everyone in my family thinks that way, then nothing gets done.
And these types of dilemmas are everywhere from the siding, whether to recycle to taking the car or the bike to work to budget allocations in organizations and political arms races. What all these dilemmas have in common is that they create conflict now from an evolutionary. Point of view, natural selection, we have favorite individuals who favor self-interest because I would increase their survival chances and also economic models portray irrational agents as Homo economics who maximize the self-interest. But despite this strong temptation to the effect, we cooperate readily. We share with one another. We give to each other, seemingly without getting anything in return.
So tonight, I want to present some ideas that my colleague, crystal van and I, rolled up in a. Forthcoming book, and we propose that our brain is wired with two routes to cooperation, one driven by self interests, the other one by group inclusion. And that gives us a double nature. We are compassionate egoists, and we're constantly hovering between wanting what the script for me and wanting to see the group prosper, these two routes to cooperation or ecologically rational, and I borrowed a term from HERD gleaner to explain how real Minds work. Now our brain is a limited information capacity. Device, and if it would be unwise to use an infinitely long information search to make decisions.
And instead evolution has endowed us with a set of simple decision rules or heuristics that help us solve recurrent problems based on a few important features of the environment, that's. What ecological rationality is all about it's about making sound satisfactory decisions instead of trying to reach the impossible optimal. So on average heuristics improve decision-making, and they're more efficient, but. They don't take over decision-making, and when they're used outside the environment in which they were designed to operate, they might actually lead us astray and be prone to error, and I'll return to that point later.
Now, the heuristics that facilitate these two routes to cooperation were shaped throughout evolution to fulfill two basic fundamental human motives. The first motive is to serve self-interest, and it was shaped by natural selection action on the individual. You shape behavior to be.
Selfish unless there are cooperative incentives to not be selfish to cooperate. And that leads to the first decision rule be selfish, unless there are cooperating center. The second decision rule is to fulfill the motive of group inclusion and to fulfill our desire to belong. And it was shaped by natural selection by kin selection and gene-culture. Co-Evolution airy pressures to have humans maintain affiliate of bounds with those we care for and to facilitate cooperation for the well-being of the. Group, but it's unlikely that evolution would have created our behavior to be self-destructive. So if we're going to cooperate for the sake of the group, we want to make sure that our cooperative efforts will not be compromised.
So we look for trust ignore. And that leads to the second decision rule be cooperative unless your partner is untrustworthy. Now as long as group interest, coincides with personal interests, there is no conflict of motives. And these two heuristics will lead to the same behavior. For example, if you get a tax deduction for donating to charity now, I pay to be generous, but mostly pursuing self-interest, jeopardizes our social inclusion because people don't like us to be selfish and vice versa. Some people want to belong so much. They hurt themselves in the process.
And when there is a conflict of motives like that, then whether I'm going to decide to which the fission rule I'm going to abide by will depends on social values, do I like economic benefits better or do I like. Group inclusion more and schematically. It looks like this social values reflect how much we care about other people compared to ourselves. And they contrast the pro-social people versus the more greedy ones, the pro sells. And these social values are a compass in decision-making, because they guide our attention towards either tress signals in the environments or cooperative incentives, pro-social czar, naturally already cooperatives. So they care a lot about trust signals to make sure they won't be.
Betrayed when they cooperate, whereas Pro cells scan the environments for cooperative incentives. They want to know what's in it for me. Now, this cooperative incentives can be rewards for good behavior like the tax deduction for donating to charity.
But it can also be the fruits from a long-term reciprocal beneficial relationship, or they can be reputation benefits, because we all tend to cooperate more when we know we're being watched. Because at that time, we know our reputation is at stake. These.
Cooperative incentives and trust signals, they're processed by regions in the brain that I've conveniently labeled under the umbrella term, social cognition and cognitive control. And these regions, they modulate the valuation system, or the reward system of the brain where rewards of different entities are compared now do I like the warm glow of giving better or do I like the study bank accounts. And depending on the anticipated rewards, I will decide to cooperate or not. Now we test this proposition.
In a population of 322 students, and we found indeed in the upper graph that trash signals increase the co-operative behavior of pro-social, you know, they have absolutely no impact on the pro' cells. We manipulate a trust by having half the participants meet prior to the experiment. So they could get to know each other and the other half, which will whom we compare their behavior state just plainly anonymous. And then we manipulated cooperative incentives. And we did that by having the participants. Play to difference economic games that varied in payoff structure, one game elicited a strong temptation to defect. And the other game gave cooperative incentives.
And there we found that the co-operative incentives impact that especially the cooperative behavior of the pro cells. Now note in the lower, whereas that everybody tends to cooperate more when cooperative incentives are present. But their impact is the greatest on the pro cells who cooperate very little without them. Then we repeated this. Last experiment with the incentives under the fMRI scanner. And we found again that the pattern of neural activation in the brain differed in accordance with social values for pro cells, we found more activations in those cognitive control regions, which is consistent with defining that Pro cells adapt their behavior when the incentives are present or not.
And for pro socials, we found more activation in a region of the brain that had previously been associated with routine moral judgments. So to. Recapitulate our paradoxical nature can be traced back to the brain, which helps us to decide to cooperate when it is a lucrative making it economically rational, or when there's sufficient trust signals.
So we know we're not going to be betrayed making it socially rational. And in the in addition to these different brain regions that sustain these two routes of cooperation, different neural chemicals may be involved as well. And especially oxytocin may be interested in this respect oxytocin is a. Hormone which is produced naturally by our bodies, and it has an important role or its primary role is in reproduction in women in initiates birth, and it's released during lactation during which time it strengthens, the mother-infant bond with a search of recent experiments in economics, in psychology have shown that oxytocin can also promote bonding and trusting in more distantly related people. However, the effect of oxytocin on cooperative behavior is not unconditional. And in one of our. Experiments, we found that oxytocin actually increases the cooperative behavior of with a partner.
But only if the partner is a familiar other person someone that you met before. And if the partner is anonymous, then oxytocin actually significantly decreases cooperation. And other experiments have shown that oxytocin promotes favoritism or what we call parochial behavior. It increases cooperation with in-group members.
But sometimes at the detriment of an out group, and even more interesting is that. Oxytocin may also promote ethnocentric behavior when inhaling three puffs of oxytocin, someone named Louie was found to cooperate more with Mike and Anthony, but not with someone named Ishmael or sight. So this parochial behavior is one of the first signs that cooperation heuristics may break down when they're used outside the domain in which they were designed to operate, which is a small isolated group. Now people form groups really easily based on seemingly trivial characteristics and social. Psychology experiments have corroborated over and over again, that people have a clear preference to cooperate with in-group members that they show in-group favoritism. And this in-group, favoritism or parochial behavior may have been very advantageous to our ancestors in the Pleistocene who lived in small isolated groups, um to accounts by showing their loyalty to the in-group and discriminating against an out group.
They helped the group win the competition. And if the group wins, the competition. They win economically because they share the loot they share in the economic games gains of a group that wins. But they also win socially because through a shared social identity with the group, a winning group may boost your self-esteem, your sense of self-worth. And that may make you value the group, even more the value group belonging beyond the economic benefits that they can expect from them soccer fans. For example, they don't share in the wealth of their team. They just like to see their team.
Win. They want to be part of the claim and paper people pay dues to belong to churches to support groups. And what they get in return is not money, but a sense of social security, a sense of shared identity and a strong social identity shifts, the self-image from I to us, and it's intertwines personal well-being with the well-being of the group. But when social identity is threatened that creates an us-versus-them mentality, and that is what we're currently experiencing with groups that are divided across. Religious or political ideologies, and when they become radical, they're pro-social decisions are not necessarily virtuous anymore. So how to counteract parochialism, in-group, favoritism and an ethnocentric behavior?
Clearly, if we want to sustain cooperation on a more global scale beyond boundaries, then cooperation heuristics are not sufficient and neither approach social values, because they do temper greed that's, good, then parents and schools know that. And they spend a lot of time and effort. Channelizing their youths value to be norm compliant, but the same pro-social values that help our children find their role in society and identify with society, make them prone to favoritism and parochialism.
Now in societies that are large like ours, where boundaries are diffuse, it seems that's one way to or one antidote for parochial behavior. And threaten eccentric behavior is to use conscious deliberate reasoning. What do I mean by that? Well, we can cultivate our awareness of belief, biases and. Trade them for logical analysis. We can exert impulse control, and we press the urge for a small reward now in favor of a larger one in the future.
And when we regret something we can reflect on the values that cause the regret in the first place and perhaps change paths if that's necessary, ironically, all these examples, tap the neural networks of cognitive control, which I earlier associated with selfishness and economic rationality. So economic rationality is not all bad. And social rationality is.
Not always virtuous. These are heuristics that operate without valence they're relics that we inherited from our ancestors. And if we're going to use them today, we better do so with a healthy dose of reasoning. Thank you.