Friend or Foe? A Psychological Perspective on Trust
Foundations
Contributor / Adam Waytz
Associate Professor of Management and Organizations
Kellogg School of Management / Psychology
The four key components of trust are benevolence, integrity, competence, and predictability, and there are two fundamental questions that psychologists and neuroscientists seek to answer about it. First, how do people decide to trust another person? Second, how quickly do we make that decision—how automatic is trust? Researchers have become especially interested in the role of the hormone oxytocin in fostering trust. Does it really promote social bonding, as some people have claimed, and are the studies showing these results replicable?
Transcript
I’m going to be talking about trust from the perspective of psychology, neuroscience, and psychophysiology.
And in these fields and subfields, trust is studied in a fairly straightforward manner: People want to know, and researchers want to know, under what conditions do people trust each other, and what are the factors that people use to determine whether or not to trust someone?
Now, despite the straightforward manner in which trust is studied in these fields, trust is really a multifaceted concept in these fields as well.
BUMPER: Key Components of Trust
So, drawing on a definition that actually comes from outside of psychology, from McKnight and Chervany in the information sciences, we can think about trust as consisting of four different things: benevolence, integrity, competence and predictability.
Benevolence essentially means, is this person a kind person? Integrity means, is this person an ethical person?
Competence means, does this person have the ability to do what needs to be done? And finally, predictability means, does this person behave in a way that I can consistently forecast?
The key question that people want to know about in these fields is, how do people judge whether someone or another entity is friend or foe? What are the dimensions that people use in judging whether someone is trustworthy or not?
BUMPER: Neural and Hormonal Bases for Trust
Trust is also studied in the subfields of neuroscience and psychophysiology, where these fields take psychological questions and simply ask, what are the neural or hormonal or physiological underpinnings of psychological phenomena?
The basic questions that psychology, neuroscience and psychophysiology are trying to answer are essentially twofold: One is, how do people decide whether or not to trust another person? What are the characteristics of the target? What are the situational determinants that lead someone to trust another person or not?
And second, a more recent question that people have gotten really interested in these fields is, how automatic is trust? How quickly do we make the decision to trust another person?
So, one of the debates that predominates psychology is the degree to which trust truly is automatic — that is, how quickly do we judge another person as trustworthy or untrustworthy.
A second debate in this field focuses on a much more specific topic, which is the topic of, what is oxytocin’s role in guiding trust?
Oxytocin is this hormone that’s been implicated in all sorts of behaviors related to social bonding and affiliation.
And work in the early 21st century by Paul Zak and colleagues determined that administering oxytocin to people (that is, increasing people’s oxytocin) increased their willingness to trust people.
But more recent research has questioned, how much is oxytocin actually solely positive in nature? Is it really this “love drug” that people like to refer to it as?
Another questions is, how much are the studies that show the role of oxytocin and trust, how much are those studies able to replicate when administered time and time again?
BUMPER: Measuring Trust
How people measure trust and trusting behavior in psychology and neuroscience and psychophysiology is very straightforward. Often, it simply consists of asking people, “How much do you trust this person, on a one-to-seven scale where one is not at all and seven is very much?”
So, a typical study would present people with various targets — maybe targets that they are just viewing the face of, maybe targets that they’ve interacted with — and then the study would ask people, “How much do you trust this person?”
Other research uses classic economic games. There’s one game that’s known as the “investment game,” or the “trust game,” that can actually measure trusting behavior.
So, within the field of psychology and its associated fields of neuroscience and psychophysiology, the questions that we’re asking about trust are really relatively simple: How do people decide and how quickly do people decide whether or not to trust another person?
However, the way that trust can be conceptualized is incredibly multifaceted.
So, trust might mean trust in the predictability of someone, trust in the warmth or benevolence of someone, trust in the integrity of someone, or trust in the competence of someone to get things done.
And in these fields and subfields, trust is studied in a fairly straightforward manner: People want to know, and researchers want to know, under what conditions do people trust each other, and what are the factors that people use to determine whether or not to trust someone?
Now, despite the straightforward manner in which trust is studied in these fields, trust is really a multifaceted concept in these fields as well.
BUMPER: Key Components of Trust
So, drawing on a definition that actually comes from outside of psychology, from McKnight and Chervany in the information sciences, we can think about trust as consisting of four different things: benevolence, integrity, competence and predictability.
Benevolence essentially means, is this person a kind person? Integrity means, is this person an ethical person?
Competence means, does this person have the ability to do what needs to be done? And finally, predictability means, does this person behave in a way that I can consistently forecast?
The key question that people want to know about in these fields is, how do people judge whether someone or another entity is friend or foe? What are the dimensions that people use in judging whether someone is trustworthy or not?
BUMPER: Neural and Hormonal Bases for Trust
Trust is also studied in the subfields of neuroscience and psychophysiology, where these fields take psychological questions and simply ask, what are the neural or hormonal or physiological underpinnings of psychological phenomena?
The basic questions that psychology, neuroscience and psychophysiology are trying to answer are essentially twofold: One is, how do people decide whether or not to trust another person? What are the characteristics of the target? What are the situational determinants that lead someone to trust another person or not?
And second, a more recent question that people have gotten really interested in these fields is, how automatic is trust? How quickly do we make the decision to trust another person?
So, one of the debates that predominates psychology is the degree to which trust truly is automatic — that is, how quickly do we judge another person as trustworthy or untrustworthy.
A second debate in this field focuses on a much more specific topic, which is the topic of, what is oxytocin’s role in guiding trust?
Oxytocin is this hormone that’s been implicated in all sorts of behaviors related to social bonding and affiliation.
And work in the early 21st century by Paul Zak and colleagues determined that administering oxytocin to people (that is, increasing people’s oxytocin) increased their willingness to trust people.
But more recent research has questioned, how much is oxytocin actually solely positive in nature? Is it really this “love drug” that people like to refer to it as?
Another questions is, how much are the studies that show the role of oxytocin and trust, how much are those studies able to replicate when administered time and time again?
BUMPER: Measuring Trust
How people measure trust and trusting behavior in psychology and neuroscience and psychophysiology is very straightforward. Often, it simply consists of asking people, “How much do you trust this person, on a one-to-seven scale where one is not at all and seven is very much?”
So, a typical study would present people with various targets — maybe targets that they are just viewing the face of, maybe targets that they’ve interacted with — and then the study would ask people, “How much do you trust this person?”
Other research uses classic economic games. There’s one game that’s known as the “investment game,” or the “trust game,” that can actually measure trusting behavior.
So, within the field of psychology and its associated fields of neuroscience and psychophysiology, the questions that we’re asking about trust are really relatively simple: How do people decide and how quickly do people decide whether or not to trust another person?
However, the way that trust can be conceptualized is incredibly multifaceted.
So, trust might mean trust in the predictability of someone, trust in the warmth or benevolence of someone, trust in the integrity of someone, or trust in the competence of someone to get things done.
Related Videos
Measuring Trust: Through Competence—or Warmth?
Applications
Contributor / Adam Waytz
Adam Waytz
Psychology
Breaches,Distrust,Government,Leadership,Measurement,Reputation Management,Social Psychology
BUMPER: Trust and First Impressions
I think what the research suggests is that first impressions go a long way and that people are making a decision about, “Do I trust this person? Do I trust this organization? Do I trust this brand?” relatively immediately.
And furthermore, trust is very difficult to restore once it is breached.
BUMPER: Warmth vs. Competence in Gauging Trust
So, the work of Susan Fisk and others has shown that warmth really predominates judgments of trustworthiness, more so than competence.
So, the first and the most important thing that people are basing their judgments of trust on are, “Do I feel that this is someone that’s benevolent? Is this a person or a company or a brand that’s kind, that’s good, that I would like to be friends with?”
The problem is, in the world of business, people tend to focus on conveying competence.
When they want to restore trust or when they want to gain people’s trust initially, businesses tend to focus on competence: letting people know that they’re intelligent, that they’re capable, that they have the ability to act on whatever their intentions are.
Consumers and people in the world and just people who are engaged in social life care about competence second. They care about warmth first. This is also important for leaders as well.
Amy Cuddy and colleagues wrote an article in Harvard Business Review that I like to refer to which is called “Connect, Then Lead.”
Often leaders think that they need to convey their competence to the organization above all else. But the most important thing is first to connect with subordinates and peers and other executives on this dimension of warmth.
I think why we focus so much on competence in the world of business is that competence is much easier to measure. We can see performance ratings; we can see sales numbers; we can see return on investment.
Competence is something that is very visible, so we tend to focus on what is visible and what’s quantifiable.
Warmth is something that feels a bit squishier, a bit more abstract, and even a bit less quantifiable, yet warmth is what people are really thinking about when they’re judging, “Do I trust this person? Do I trust this organization? Do I trust this brand?”
Now, some companies and some organizations have gotten much better at quantifying warmth or quantifying things like social responsibility: “How much is my organization engaged in fair practices towards its workers? Positive interactions with the community? Benevolent actions towards the environment?”
And we can start seeing the emergence of the corporate social responsibility scores. I think this is a step forward in organizations trying to capture warmth in a more quantifiable manner and then conveying that to potential consumers who really care about these dimensions.
I think what the research suggests is that first impressions go a long way and that people are making a decision about, “Do I trust this person? Do I trust this organization? Do I trust this brand?” relatively immediately.
And furthermore, trust is very difficult to restore once it is breached.
BUMPER: Warmth vs. Competence in Gauging Trust
So, the work of Susan Fisk and others has shown that warmth really predominates judgments of trustworthiness, more so than competence.
So, the first and the most important thing that people are basing their judgments of trust on are, “Do I feel that this is someone that’s benevolent? Is this a person or a company or a brand that’s kind, that’s good, that I would like to be friends with?”
The problem is, in the world of business, people tend to focus on conveying competence.
When they want to restore trust or when they want to gain people’s trust initially, businesses tend to focus on competence: letting people know that they’re intelligent, that they’re capable, that they have the ability to act on whatever their intentions are.
Consumers and people in the world and just people who are engaged in social life care about competence second. They care about warmth first. This is also important for leaders as well.
Amy Cuddy and colleagues wrote an article in Harvard Business Review that I like to refer to which is called “Connect, Then Lead.”
Often leaders think that they need to convey their competence to the organization above all else. But the most important thing is first to connect with subordinates and peers and other executives on this dimension of warmth.
I think why we focus so much on competence in the world of business is that competence is much easier to measure. We can see performance ratings; we can see sales numbers; we can see return on investment.
Competence is something that is very visible, so we tend to focus on what is visible and what’s quantifiable.
Warmth is something that feels a bit squishier, a bit more abstract, and even a bit less quantifiable, yet warmth is what people are really thinking about when they’re judging, “Do I trust this person? Do I trust this organization? Do I trust this brand?”
Now, some companies and some organizations have gotten much better at quantifying warmth or quantifying things like social responsibility: “How much is my organization engaged in fair practices towards its workers? Positive interactions with the community? Benevolent actions towards the environment?”
And we can start seeing the emergence of the corporate social responsibility scores. I think this is a step forward in organizations trying to capture warmth in a more quantifiable manner and then conveying that to potential consumers who really care about these dimensions.
The Importance of First Impressions and Trust: Key Findings
Research
Contributor / Adam Waytz
Adam Waytz
Psychology
Definitions,Reputation Management,Swift Trust
A lot of the key articles in psychology on the topic of trust I think have really come out in the 21st century. And one really key article that emerged in 2006 was a study in Psychological Science by Willis and Todorov.
And Willis and Todorov conducted a really elegant study that simply discovered the remarkable finding that trust is something that people tend to judge in another person’s face within 100 milliseconds.
Now, how they conducted this study was they gave participants a variety of different faces — they exposed participants to a variety of different male and female faces.
And the first part of the study just involved an unconstrained session where participants made various judgments about these faces.
So, how attractive is the person in this photograph? How likeable is the person in this photograph? And how trustworthy is the person in this photograph?
In the second portion of the study, participants were presented with the same faces extremely rapidly. So, some were presented at 100 milliseconds; some were presented at 500 milliseconds; and some were presented at 1 second.
And various participants, after this brief exposure to the face, were simply asked the question, “Do you find this person trustworthy, yes or no?”
And what they found was very striking. First of all, there was an extremely high correlation between these snap judgments of, “Do I judge this person as trustworthy, yes or no?” after just a brief exposure to a face — a monumental correlation with those judgments and the judgments made in the absence of time constraints.
So, this suggests that people are making judgments about trustworthiness within 100 milliseconds.
What was also interesting was that, as time increased (so, as participants saw these faces at 500 milliseconds or after a whole second), the correlation didn’t really change that much.
So, what these findings tell us is that trustworthiness is something that people judge very automatically, even before we’ve gotten our wits together to really decide how confident we are in our judgment.
And they really correspond to the same judgments we make about trustworthiness when we have unlimited time to judge people.
BUMPER: Key Research on Trust in Neuroscience
Neuroscientists have also really taken up the topic of trust in their studies as well. One definitive paper on the neural underpinnings of trusting behavior comes from Krueger and colleagues, published in Proceedings of the National Academy of Sciences.
This experiment involved a multi-round trust game. So, this is the game where there is an investor that decides how much money to invest with a trustee, and the trustee then decides how much to pay back.
In these studies, the trust game is administered in a similar fashion to how it’s administered in classic psychological studies, in studies within economics; the only difference, of course, was that in this study, participants brains were scanned while they were making decisions about whether or not to trust and how much to trust people.
The central findings of these studies were that there was a central network of brain regions that was involved in decisions about whether or not to trust, and these brain regions are those that are typically involved in what is called “mentalizing,” or thinking about the mind of another person, thinking about the intentions of another person.
So, this mentalizing network was consistently recruited when people were making decisions about whether or not to trust.
What was also interesting was that this study looked at the differences between conditional trust and unconditional trust.
What’s meant by conditional trust is trust with the assumption that my partner in this game might behave in a self-interested fashion. Conditional trust is, I’m only going to trust you if you’re going to repay me, repay my trust.
Unconditional trust has to do with trusting people indiscriminately, irrespective of what you think their intentions might be.
Another major finding of this study was that separate brain networks were recruited when people engaged in conditional versus unconditional trust, suggesting that these are different psychological processes.
BUMPER: Warmth vs. Competence
A short review paper in Trends in Cognitive Sciences by Susan Fisk, Amy Cuddy and Peter Glick really summarizes a body of research that is essential to understanding how psychologists think about trust and how psychologists study trust in this day and age.
What Fisk and colleagues have found over years and years of studies is that we essentially judge people on two dimensions: How warm is this person? So, how benevolent is this person? And how competent is this person? Does this person have the capability of acting on his or her intentions?
And the most interesting finding that comes out of this research is that people don’t treat warmth and competence the same.
People judge these things relatively rapidly; they base a lot of their judgments about whether to approach or avoid another person on judgments of warmth and competence. But warmth tends to predominate our social judgments.
In other words, warmth is the first thing that we judge when we judge another person (competence comes slightly after), and warmth carries the weight of our judgments when deciding whether or not to trust someone.
And Willis and Todorov conducted a really elegant study that simply discovered the remarkable finding that trust is something that people tend to judge in another person’s face within 100 milliseconds.
Now, how they conducted this study was they gave participants a variety of different faces — they exposed participants to a variety of different male and female faces.
And the first part of the study just involved an unconstrained session where participants made various judgments about these faces.
So, how attractive is the person in this photograph? How likeable is the person in this photograph? And how trustworthy is the person in this photograph?
In the second portion of the study, participants were presented with the same faces extremely rapidly. So, some were presented at 100 milliseconds; some were presented at 500 milliseconds; and some were presented at 1 second.
And various participants, after this brief exposure to the face, were simply asked the question, “Do you find this person trustworthy, yes or no?”
And what they found was very striking. First of all, there was an extremely high correlation between these snap judgments of, “Do I judge this person as trustworthy, yes or no?” after just a brief exposure to a face — a monumental correlation with those judgments and the judgments made in the absence of time constraints.
So, this suggests that people are making judgments about trustworthiness within 100 milliseconds.
What was also interesting was that, as time increased (so, as participants saw these faces at 500 milliseconds or after a whole second), the correlation didn’t really change that much.
So, what these findings tell us is that trustworthiness is something that people judge very automatically, even before we’ve gotten our wits together to really decide how confident we are in our judgment.
And they really correspond to the same judgments we make about trustworthiness when we have unlimited time to judge people.
BUMPER: Key Research on Trust in Neuroscience
Neuroscientists have also really taken up the topic of trust in their studies as well. One definitive paper on the neural underpinnings of trusting behavior comes from Krueger and colleagues, published in Proceedings of the National Academy of Sciences.
This experiment involved a multi-round trust game. So, this is the game where there is an investor that decides how much money to invest with a trustee, and the trustee then decides how much to pay back.
In these studies, the trust game is administered in a similar fashion to how it’s administered in classic psychological studies, in studies within economics; the only difference, of course, was that in this study, participants brains were scanned while they were making decisions about whether or not to trust and how much to trust people.
The central findings of these studies were that there was a central network of brain regions that was involved in decisions about whether or not to trust, and these brain regions are those that are typically involved in what is called “mentalizing,” or thinking about the mind of another person, thinking about the intentions of another person.
So, this mentalizing network was consistently recruited when people were making decisions about whether or not to trust.
What was also interesting was that this study looked at the differences between conditional trust and unconditional trust.
What’s meant by conditional trust is trust with the assumption that my partner in this game might behave in a self-interested fashion. Conditional trust is, I’m only going to trust you if you’re going to repay me, repay my trust.
Unconditional trust has to do with trusting people indiscriminately, irrespective of what you think their intentions might be.
Another major finding of this study was that separate brain networks were recruited when people engaged in conditional versus unconditional trust, suggesting that these are different psychological processes.
BUMPER: Warmth vs. Competence
A short review paper in Trends in Cognitive Sciences by Susan Fisk, Amy Cuddy and Peter Glick really summarizes a body of research that is essential to understanding how psychologists think about trust and how psychologists study trust in this day and age.
What Fisk and colleagues have found over years and years of studies is that we essentially judge people on two dimensions: How warm is this person? So, how benevolent is this person? And how competent is this person? Does this person have the capability of acting on his or her intentions?
And the most interesting finding that comes out of this research is that people don’t treat warmth and competence the same.
People judge these things relatively rapidly; they base a lot of their judgments about whether to approach or avoid another person on judgments of warmth and competence. But warmth tends to predominate our social judgments.
In other words, warmth is the first thing that we judge when we judge another person (competence comes slightly after), and warmth carries the weight of our judgments when deciding whether or not to trust someone.
The Nature of Trust: A Philosopher’s Perspective
Foundations
Contributor / Sanford Goldberg
Sanford Goldberg
Philosophy
Definitions,Distrust,Reciprocity,Regulation
Trust is a topic that’s of great interest to philosophers. In philosophy, two subfields typically look at trust. One of them is ethics, and the other is the theory of knowledge, which is also known as “epistemology.”
The topics that philosophers look into, when they look into trust, are three: the nature of trust, the rationality of trust, and the ethics of trust. And, in this brief segment, what I thought I would do is run through all three.
When it comes to the nature of trust, philosophers are very interested in distinguishing trust from dependence and reliance. It’s a controversial issue whether trust is actually distinct from dependence or reliance, or if it’s just a type of dependence or reliance.
Most philosophers think that it’s a type of reliance, and the question is, how does it differ from mere reliance on someone?
And one of the key insights — if in fact it is an insight — of philosophers who think about trust is that trust is a kind of reliance that gives rise not merely to disappointment but to a sense of betrayal when one’s trust is violated.
And really, philosophers interested in the nature of trust ask what kind of thing is trust, such that violations of that trust yield a sense of betrayal rather than mere disappointment?
Philosophers interested in the nature of trust also are interested in the varieties of trust. And here, they distinguish between main types. The main type is what we would call “practical trust” — that’s trusting someone or some institution to do something or to be a certain way, or to refrain from doing something or to refrain from being a certain way.
The other variety of trust is what philosophers call “intellectual” or “epistemic trust,” which is the kind of trust that you have in a person or a source of information when you trust it, when you rely on it for the truth in what it tells you.
Many people think that epistemic or intellectual trust is a special case of practical trust, and that is an issue that philosophers will discuss at great length in a variety of different ways.
When it comes to the rationality of trust, we need to distinguish between two types of rationality. The first type I would call “practical rationality.” Practical rationality is the sort of rationality when it’s in your interest to do something — so, it’s rational when it’s in your interest to do something.
You might ask, when is it practically rational to trust? And here, the answer will again depend on what kind of cost-benefit analysis you do. Suppose that if you trust someone, then he or she will be your friend. That’s obviously a good thing, and that goes on the benefit side.
Suppose that you’ll have lots of friends. That makes it very, very good to trust. These are the kinds of considerations that might actually make it practically rational to trust.
But you can take a different attitude towards the rationality of trust. Suppose what you’re primarily interested in is acquiring true beliefs and avoiding false beliefs. Less interested in things like friendship or other kinds of goodies, instead you’re interested in acquiring true beliefs and avoiding false beliefs.
There, it’s clear that whether or not trusting someone will make them your friend is irrelevant to the kind of belief you want to acquire. Here, we need to talk about epistemic rationality.
What are the conditions under which trust is epistemically rational? Here, philosophers divide into two main camps. One of the camps holds that it’s rational to trust another person — so, to believe what they say — only if you have good independent reasons to regard them as trustworthy.
This view — which in philosophical circles is known as “reductionism” — holds that it’s only when you have those good reasons that it’s rational to trust someone. Those reasons can take a variety of forms.
Perhaps you know someone’s track record. They’re highly reliable, and they’ve been highly reliable in the past, so they’re likely to be reliable on this occasion. Perhaps they look sincere and competent. Those can be reasons to trust.
Other philosophers disagree. They think that you don’t need positive reasons to trust another person; what’s necessary instead is that you lack reasons to regard them as untrustworthy.
They hold, for example, that it’s rational to trust another speaker, in the same way that it’s rational to trust your own perceptual resources, when you don’t have reasons to regard the relied-upon source as untrustworthy — that is, when you don’t have reasons to think that the person with whom you’re interacting is actually unreliable or incompetent or insincere.
That view is known as “antireductionism,” and that’s the opposing view of the reductionist view about the rationality of trust.
I move on now to the final issue that philosophers explore when we think about the nature of trust, and that is the ethics of trust. I take it that it’s uncontroversial to think that we all have ethical obligations to be trustworthy.
For example, we all take it, I suppose, that you shouldn’t lie and you shouldn’t say things for which you don’t have adequate evidence. That’s not particularly controversial.
The more controversial and interesting question arises when we ask whether we have ethical obligations to trust others. Why would you think that you do have ethical obligations to trust others?
Some philosophers remind us, for example, that friendships or loving relationships can require trust on the part of the two people involved. For example, if you have a friend but don’t trust her, that may well undermine the friendship.
Or if you have a partner or a spouse and you don’t trust him, that may undermine the relationship that you have.
These philosophers use these kinds of relationships to suggest that we are sometimes under ethical obligations to trust others.
There’s one case that philosophers use to think about the question about the relationship between the ethics of trust and the rationality of trust. Take a case in which a child of yours or perhaps a very good friend is accused of a horrific crime. And he or she swears to you that he or she is innocent — not guilty as charged.
And now imagine that the evidence that’s out there is rather substantial and suggests that the person is in fact guilty. If we think that there are ethical obligations to trust our friends or our children, then we reach an interesting conclusion that it may be ethically required of us to believe something that flies in the face of the evidence.
And that is grounds for some interesting philosophical discussion.
The topics that philosophers look into, when they look into trust, are three: the nature of trust, the rationality of trust, and the ethics of trust. And, in this brief segment, what I thought I would do is run through all three.
When it comes to the nature of trust, philosophers are very interested in distinguishing trust from dependence and reliance. It’s a controversial issue whether trust is actually distinct from dependence or reliance, or if it’s just a type of dependence or reliance.
Most philosophers think that it’s a type of reliance, and the question is, how does it differ from mere reliance on someone?
And one of the key insights — if in fact it is an insight — of philosophers who think about trust is that trust is a kind of reliance that gives rise not merely to disappointment but to a sense of betrayal when one’s trust is violated.
And really, philosophers interested in the nature of trust ask what kind of thing is trust, such that violations of that trust yield a sense of betrayal rather than mere disappointment?
Philosophers interested in the nature of trust also are interested in the varieties of trust. And here, they distinguish between main types. The main type is what we would call “practical trust” — that’s trusting someone or some institution to do something or to be a certain way, or to refrain from doing something or to refrain from being a certain way.
The other variety of trust is what philosophers call “intellectual” or “epistemic trust,” which is the kind of trust that you have in a person or a source of information when you trust it, when you rely on it for the truth in what it tells you.
Many people think that epistemic or intellectual trust is a special case of practical trust, and that is an issue that philosophers will discuss at great length in a variety of different ways.
When it comes to the rationality of trust, we need to distinguish between two types of rationality. The first type I would call “practical rationality.” Practical rationality is the sort of rationality when it’s in your interest to do something — so, it’s rational when it’s in your interest to do something.
You might ask, when is it practically rational to trust? And here, the answer will again depend on what kind of cost-benefit analysis you do. Suppose that if you trust someone, then he or she will be your friend. That’s obviously a good thing, and that goes on the benefit side.
Suppose that you’ll have lots of friends. That makes it very, very good to trust. These are the kinds of considerations that might actually make it practically rational to trust.
But you can take a different attitude towards the rationality of trust. Suppose what you’re primarily interested in is acquiring true beliefs and avoiding false beliefs. Less interested in things like friendship or other kinds of goodies, instead you’re interested in acquiring true beliefs and avoiding false beliefs.
There, it’s clear that whether or not trusting someone will make them your friend is irrelevant to the kind of belief you want to acquire. Here, we need to talk about epistemic rationality.
What are the conditions under which trust is epistemically rational? Here, philosophers divide into two main camps. One of the camps holds that it’s rational to trust another person — so, to believe what they say — only if you have good independent reasons to regard them as trustworthy.
This view — which in philosophical circles is known as “reductionism” — holds that it’s only when you have those good reasons that it’s rational to trust someone. Those reasons can take a variety of forms.
Perhaps you know someone’s track record. They’re highly reliable, and they’ve been highly reliable in the past, so they’re likely to be reliable on this occasion. Perhaps they look sincere and competent. Those can be reasons to trust.
Other philosophers disagree. They think that you don’t need positive reasons to trust another person; what’s necessary instead is that you lack reasons to regard them as untrustworthy.
They hold, for example, that it’s rational to trust another speaker, in the same way that it’s rational to trust your own perceptual resources, when you don’t have reasons to regard the relied-upon source as untrustworthy — that is, when you don’t have reasons to think that the person with whom you’re interacting is actually unreliable or incompetent or insincere.
That view is known as “antireductionism,” and that’s the opposing view of the reductionist view about the rationality of trust.
I move on now to the final issue that philosophers explore when we think about the nature of trust, and that is the ethics of trust. I take it that it’s uncontroversial to think that we all have ethical obligations to be trustworthy.
For example, we all take it, I suppose, that you shouldn’t lie and you shouldn’t say things for which you don’t have adequate evidence. That’s not particularly controversial.
The more controversial and interesting question arises when we ask whether we have ethical obligations to trust others. Why would you think that you do have ethical obligations to trust others?
Some philosophers remind us, for example, that friendships or loving relationships can require trust on the part of the two people involved. For example, if you have a friend but don’t trust her, that may well undermine the friendship.
Or if you have a partner or a spouse and you don’t trust him, that may undermine the relationship that you have.
These philosophers use these kinds of relationships to suggest that we are sometimes under ethical obligations to trust others.
There’s one case that philosophers use to think about the question about the relationship between the ethics of trust and the rationality of trust. Take a case in which a child of yours or perhaps a very good friend is accused of a horrific crime. And he or she swears to you that he or she is innocent — not guilty as charged.
And now imagine that the evidence that’s out there is rather substantial and suggests that the person is in fact guilty. If we think that there are ethical obligations to trust our friends or our children, then we reach an interesting conclusion that it may be ethically required of us to believe something that flies in the face of the evidence.
And that is grounds for some interesting philosophical discussion.