Is there a “trust spot” in the brain? How do we balance the human desire to trust against the fear of betrayal? Dr. Frank Krueger, a psychologist, physicist, and neuroscientist at George Mason University, explains how our brain circuits teach us to navigate the social dilemma of who deserves our trust. Plus… why men are more trusting (and take more risks) than women, and why those with autism have so much trouble deciding whom to trust.
Phil Stieg: Hello, I’d like to welcome Dr. Frank Krueger, professor of Systems neuroscience at George Mason University. He studies psychological functions and neurobiological mechanisms of social cognition, particularly related to trust and cooperation. Frank, welcome, and thanks for being here.
Frank Krueger: Yeah, it’s my pleasure. Thank you for having me.
Phil Stieg: So tell me, what is trust?
Frank Krueger: Yeah. So it’s actually it’s very important because if you want to look into the brain, right, you need a good definition about what you are studying? So what the idea is that when you trust somebody else, you make yourself vulnerable to the other person. And basically at the same time, you have to have an expectation that the other person will follow through and maybe repay your trust so that there’s a positive outcome. And then if you look at the brain, you actually see that different types of trust actually trigger different components of this trust definition that I just gave.
Phil Stieg: Well, that’s where I wanted to go. I always rely on the line by Ronald Reagan, you know, “trust but verify”. And you implied that there are different kinds of trust. Please elaborate on that.
Frank Krueger: I think we have three different levels of trust. There’s calculus-based trust, that’s knowledge-based trust and identification- based trust. So it’s a kind of trust evolution that I go from one stage to the other one and we start we have to start the relationship so that we can cooperate. And this is called a calculus-based trust. So in that moment, you have no information about the other person, but you have to trust the person. And there you make rational calculation based on costs and benefits and you are using your propensity to trust and follow through. In this moment, you would start the relationship.
Then you go to the next level, which you called knowledge-based trust. So here I interact with the other person over different rounds and in different environments, in different situations. So I develop a picture about how you trust how trustworthy you are. So we continue pushing our relationship further., then we go off to the identification-based trust. So I’m a few actually. We’re not interacting with you as soon as I see you already. I know that I can trust you and I can follow through into action. And this is actually what people most refer to as “trust” – this identification-based trust.
Phil Stieg: What role does facial expression play in trust?
Frank Krueger: In the blink of an eye, we can actually see if people are trustworthy, so but that doesn’t mean that they are actually trustworthy, right? So some people look trustworthy, but using this as a cue and you might go in one direction on that one. But this is a cue if you don’t have anything, people using these kinds of cues just to initiate the trust.
Phil Stieg: So if you’re a grifter or a con man, you’re really working on developing those characteristics that are viewed as, quote, trustworthy, i.e., facial expressions, body motion.
Frank Krueger: Yeah, and I mean, again, based on Covid 19 there’s now studies where they give people a mask and see if they trust the person. And basically a trustworthy face. It’s described here in the eyeballs, but also around the mouth in the chin. So if you cover it, people have actually a problem to recognize this trustworthy face.
Phil Stieg: Can society exist without trust? Are there any societies where people are just completely non trusting?
Frank Krueger: I think you wouldn’t be here. I think it’s the main building block, for each society, each group.
Phil Stieg: And what about the individual that has a difficult time with trusting? Can you be taught how to trust?
Frank Krueger: I think you can because what we showed is it has different components. So what we’re doing is we look at the neuroscience, but also we have behind it psychological theory and there we determine what actually makes trust. Basically there is a social dilemma. So I might be vulnerable. So there is like a betrayal. The person might betray you. But also if the person reciprocate my trust, I’m better off – I have a reward. And those components create kind of uncertainty. And then you have to overcome the uncertainty. You think about, OK, how trustworthy is a person? So I can decide to trust or you interact strategically with the person. And each of those has different networks in the brain, and depending on those, if you are lacking those, for example, people with autism, they cannot put yourself too much in your shoes. So they have problem to estimate your trustworthiness.
Phil Stieg: Being the scientist that you are, you’re looking at trust from a psychological and a biological perspective. Is trust an emotion? And then if or if it is not, then what are the psychological and biological perspectives that you’re looking at or measuring?
Frank Krueger: Actually, we look at from three parts, I call it “neuropsych economics” of trust. So, on the one hand we have the economics paradigms. So we are using exchange games to measure trust. And because those gives us a nice mathematical theory to actually model of Strategic Decision-Making, that helps us actually to measure trust as a behavior. My background is psychology, So I’m interested in what are the processes that leads you to trust that person. Here we are looking at the motivation, the effect and also the cognition behind it. There are three levels, the neural functional level. So you can look at the brain circuits that are underlying trust on a new chemical level. So what kind of hormones are neurotransmitter are triggering trust? And then also we look at a neural-genetics level. So what kind of genetics are behind the trust?
Phil Stieg: I find it interesting that you use economics or money to assess level of trust. I’m presuming that’s because it’s an easy metric to measure and it’s an easy thing for an individual to get their mind and their arms around as to whether they want to trust another person in that regard.
So give me an example of what you ask of a person. You know, you need to say, is it a betting scheme? Is it what do you do? And then what do you what do you measure?
Frank Krueger: As I said, we’re using these exchange games from economics. The typical one we’re using here is called the trust game or also sometimes called the investment game. There’s a “truster” and there’s a “trustee” and the” truster” gets an endowment of money, let’s say ten dollars. And that person can now send the money over to the trustee, then the experimenter triples this amount. And now the other person can just send any money back that the other person sent over and it was tripled. So let’s have an example. Let’s say we play together the trust game and you would get ten dollars now and now you can decide you want to send any money back to me, you can keep it. Then the game would be over. There would be no social interaction. If you send money over, let’s say you would send five. And this is what most people send over. So that amount gets triple. So I got fifteen now. And now any of the fifteen I can send back to you. But here’s the catch. You make yourself more vulnerable because I can also finish the game and keep all the fifteen now and don’t have to send anything back. And that would be the kind of betrayal. But if I send something back and most people send also half of that amount back at the end, you are better off and I better off. And that’s why it’s worthwhile trusting each other.
Phil Stieg: So is that trust or is that just playing odds? I mean, the person knows they’re playing a game and they’re going to see how long this kind of keeps going on. And, you know, if you do “halfsies” all the time and you go five than you do, then you go to seven and, you know, just keeps multiplying. I don’t understand how we’re measuring trust with that.
Frank Krueger: When we interact with another person they are really afraid of the other person might betray you. And now you can play the game once that measures like your trust propensity, how in general you trust people. But the more interesting part is from the neuroscience, from the psychology as you play over and over. And this is where you see people develop first this calculus-based trust and they switch over to knowledge-based trust. And at the end they have a kind of affiliation with the other person.
Phil Stieg: So they’re playing with the same person?
Frank Krueger: Yes, over and over. .
This Is Your Brain: The Guided Tour – Who Do You Trust?
Phil Stieg: Earlier you said that a society couldn’t exist without trust. Can I then conclude that we as human beings are hardwired as a species to trust?
Frank Krueger: Yeah, I think if you think about it, we are the survivors of the most social people in the past. We have the social brains. And as I said before, us analysts have this kind of attachment system and they can develop a kind of identification-based trust. But now, through our brain development, we can also now establish actually trust relationship with strangers, which you wouldn’t see in other species, and that allows us to do trade with others, et cetera, and that flourished society.
Phil Stieg: Is trust intrinsically human or do animals have it as well? You know, does your dog trust you?
Frank Krueger: Yeah, so we don’t know. But actually, I read recently a very interesting publication in Animal Cognition. So they actually showed that dogs can determine the trustworthiness of their owner. So they did a little experiment where the owner showed to a bucket and if there’s food in there or not, and then they open up the bucket and the dog could see it. And after a while, if there was some misinformation, actually the dog didn’t take any advice anymore from the owners. So we could say, like in our language, basically, he could calculate the trustworthiness of the owner.
Phil Stieg: Yeah. I think you mentioned it earlier. But what clinical conditions exist where an individual either can’t trust or has limited capacity for trust?
Frank Krueger: So I mentioned autism. So there it’s more that they have problems to put themselves in the shoes of another person – taking the perspective. But all other personality disorders that has to deal with relationships. This is where trust is very important. And one key area we also are investigating is the borderline personality disorder. It’s a disorder described that they have problems to establish relationships with others. They have an impacted sense of the self and it’s very emotional. So they harm themselves and they cannot keep up these kind of relationships. And if you interview with those people and talk with them, that trust always comes up. So they have really problems established relationship and also always thinking that they might lose their relationship. So they are not able to actually building these kind of trust strategies from calculus-based or knowledge-based trust to identification-based trust.
Phil Stieg: Given the new definition that psychiatry has given to autism and it’s gone from an almost unheard-of disease to now being relatively common in society. So I’m presuming that we have a lot of work to do then in teaching people how to trust, if that’s sort of trust is a key component of autism.
Frank Krueger: A normal person, if we interact with each other, I would look you in the eyes. But autistic people, they look more around the mouth. If you give them oxytocin, it makes them more salient to your face and they look more also in their eyes. And they can also now more interact with you and also maybe trusting. So they are open themselves up to you. That doesn’t mean we should them give them oxytocin every time. But the better way is it’s a kind of intervention. That you give people oxytocin in that moment. They are more open to have this kind of relationship. And then you do a training program in that setting.
Phil Stieg: I read that there are gender differences in capacity for trust, Number one is that true, and number two, is that societal or is that genetic?
Frank Krueger: So what would you say, because people asked what you say, men are more trusting or are women more trusting?
Phil Stieg: Well, I cheated. I did some reading on this and I find that I was surprised to find that men are more trusting and they’re bigger risk takers, but women are more reciprocal.
Frank Krueger: So this has been shown basically using these kinds of games. And they did a kind of meta-analysis where they analyze like 38 different experimental settings. On average man would trust more than women. So how would you explain this? And you brought up the right keyword. This is risk taking. So if you take an evolutionary explanation, there’s this parental investment theory. So basically, we are producing and bringing up children. And who has more resources to invest? A woman has to be much more careful because they are limited to give birth to many children, etc. So they have to be cautious and they don’t want to be vulnerable. At the same time, they want to pick the right mate. So that puts a lot of pressure on the man because they have to be now competing for the mate, which is very picky, basically. And what you could say then is they have to compete in one strategy is that they’re more risk taking so that they have more resources or they have a higher social status. So basically what you would say is that the risk taking is evolutionary. But there’s also the other theory saying that’s a social role theory is that we are basically taking on these norms. So men should be more risky in society and women should be more cautious.
Phil Stieg: Can you pinpoint a spot now that we’re able to do functional MRI scans and you know, high-end EEGs and all this stuff? Is there a trust spot in the brain?
Frank Krueger: Yes, so this is always a question also I get in seminars, right? Is it one single area. It’s not and it makes sense. It’s more like a network that is engaged when you trust. So let’s think one more time. If you’re in this trust situation and you play the trust game. So the idea is you want to send money over, but at the same time you’re afraid the person may betray you. And there you see areas lighting up in a social sailence network which has areas, emotional areas like the amygdala or the insula. And if the other person sends you money back, then you feel rewarded and then you see activation in the reward center. But that’s just the uncertainty. But now I have to make that decision. So I think about your trustworthiness. I look at your face. Maybe I can see some cues there. So they’re using the default network. So this is kind of a brain area that it’s like related to social cognition. Or I can also play the whole game strategically. I don’t care about you, actually about only the money and are using a different network. It’s called the Center Executive Network. So depending on also what type of trust, you see different networks actually lighting up.
Phil Stieg: So it’s really a very complex set of neural networks that I can just imagine, and in any one issue there are different kinds of different levels of trust. So they’re going to be many different regions in the brain.
Where do you see this going then? Bk –eyond being, you know, an answer to a scientific conundrum? Do you see clinical or psychological applications from what you’re doing?
Frank Krueger: Yeah, I think the next big frontier is we’re talking about so far about human human trust, but I think human autonomy, trust, so trusting artificial agents. So in the future, we will be much more interacting with them. And I think the idea is now what we learn here between human human trust, we can maybe apply for human autonomy, trust. So, for example, we doing right now our study where we have eyeball, which is an autonomous dog, looks like and he’s interacting autonomously. And the question is, for example, can you bond to this artificial dog? And so we have studies setting up or interacting with this a social robot. So there we have to build the other system. Basically, that other system has to have these characteristics that we actually interact with the person that we see it as trustworthy. That’s on one side. And if you build also the robot, we have to program the robot that he actually also can trust us. So this is like, I think a new frontier where you can use a lot of stuff what we learned from human-human trust for this kind of trust.
Phil Stieg: We know a lot about companion dogs. I was surprised to read about, you know, artificial intelligence and robotic dogs and then being used with the elderly to provide them with some comfort. Explain that.
Frank Krueger: Yes, so, I mean, right now, it’s typically right we have covid-19 and a lot of people feel lonely, for example, and what they have done studies, they have brought these artificial dogs into nursing homes and people develop relationships. So we can get attached to these kind of artificial entities.
Phil Stieg: I see there they’re even being used in prison systems where individuals are put in solitary confinement for an extended period of time. They’re allowing them to have these robotic dogs so they have something to talk to.
Frank Krueger: Yeah. Remember, we are social beings and if you are depleted by interaction. So anything which stimulates your social brain, will actually help you to feel you feel also better.
Phil Stieg: What’s your observation, do you think that we, as a society, are we becoming less trusting?
Frank Krueger: Yeah, it looks like that people are getting more individualistic and taking care first of themselves. Because of the pandemic right now, we had a study on online and using these kinds of economic games and make sure we show because of people right now and in some sense and actually the stepped up in the behave much more altruistically in this kind of games compared in normal situations. So I think there’s hope anytime it gets too individualistic or everybody’s looking at selves at disasters or other circumstances can definitely bring us back together.
Phil Stieg: You also brought up just now an interesting observation that is trust part of a continuum. You know, I’m more trusting so that as a result of being more trusting, I’m more altruistic, which means that I’m a better member of society. Is that true?
Frank Krueger: Yeah. We talked about culture. We talked about gender. Right. But even in gender also in culture, there’s always individual differences. People, for example, who are very altruistic, or are very honest, they trust more. And people who have deficits related to fear or anxiety, they actually trust less. So it’s a personality trait. If you have high scoring on altruism or honesty, then also those people normally in these kinds of economic games, they also trust more.
Phil Stieg: What advice do you have for me to make me a more trusting individual, but also not being so trusting that I’m taken advantage of? I want to hit that sweet spot.
Frank Krueger: Yeah, you don’t take too much oxytocin (laugh). I think you have to be cognitive alert. So not just blindly trusting. F or example, something we see in older generation, in age, trust, in age. So if you get old and people trust more, but as you said, also other people can make take more advantage of the elderly.
Phil Stieg: You talked about the calculating kind of trust. Is that something where you could come up with a crib sheet? And OK, when I’m going through this scenario, if the person meets these criteria, boom, boom, boom, check them off. I say, aha, I think we have a reasonable basis upon which we can build trust.
Frank Krueger: I mean, this is you could play it, but the other person, maybe figures it out and then also plays this kind of strategic trust. Then you are in a one-way street, right?
Phil Stieg: (laugh) So people will always try to take advantage of each other.
Frank, it’s been an absolute pleasure talking with you. One wouldn’t think that the concept of trust was so complex with multiple levels and so important in terms of the fabric of who we are. I want to thank you for taking the time to be with us and really explain both the psychological and also the biological components of trust. Thanks for being here.
Frank Krueger: Thank you. You’re welcome.