Neuroscience of Trust
Welcome to Season 4 of The Brain Blown Podcast!
This month's focus: relationships
And starting with the root of any relationship: trust
Trust shapes everything we do—but it’s more complex than we think.
In a split second, our brain decides who feels safe and who doesn’t. But why?
What makes someone truly trustworthy? And why do some teams thrive while others crumble?
Let’s break it down.
And look out for more mini-episodes on this topic in the coming weeks!
If you have any topic suggestions for future episodes, don't hesitate to reach out! Send us an email at info@brainblownpodcast.com.
We'd love to hear from you.
References
Neuroscience of Trust - Paul Zak
Toward a Model of Interpersonal Trust Drawn from Neuroscience, Psychology, and Economics Frank Krueger1,* and Andreas Meyer-Lindenberg2
The Trust Game in neuroscience: A short review Hélène Tzieropoulos
Trust: A subject for Social Neuroscience Marc Schipper and Franz Petermann
Wired to Connect: Neuroscience, Relationships, and Therapy Monadekoven Fishbane, Ph.D.w
General Outline of Episode
1. Intro & Overview
On the podcast we’re looking at the neuroscience behind humanity's most powerful social force: trust.
Your brain is making trust decisions right now, as you listen to my voice. These split-second choices shaped our survival as a species, and today they shape everything from our closest relationships to our society itself.
In this month’s episode, we’ll be exploring what happens in your nervous system when trust builds - and when it breaks. You'll discover why your body sometimes screams 'danger' before your mind knows why, how stress can make it physically impossible to trust others, and the fascinating reason why feeling safe can actually make you more suspicious.
2. Theoretical Foundation
LAINE: Trust is something that sounds so simple but is so core. Schipper and Petermann state “Trust is a term which everyone knows and uses, often associated with honesty and integrity. Therefore one should think it is well defined” and go on to explain how that is very much not the case!
Fortune 500 companies and high-level leadership have started to really focus on the importance of this. It comes up in almost every family or couples therapy session. From the playground to the boardroom - we know that trust matters. Krueger and Mery-Linderberg state “Trust is a crucial component of cooperative, mutually beneficial interpersonal relationships, penetrating all human social interactions across all facets of private and public social lives”. They state that everything from relationships to society works better when we trust each other, but trust feels “unstable” because trust comes with uncertainty and fear of deception. Krueger and Mery-Linderberg state “trust encompasses one’s willingness to accept vulnerability based on the expectation regarding the behavior of another party that will produce some positive outcome in the future”. Schipper and Petermann state similar and say “Trust refers to a basic psychological concept, which relates to positive expectations under conditions providing no certainty about the outcome of events or about future interactions.”
What scientific theories or frameworks explain this issue?
What happens in the brain during this process?
LAINE: -A lot of familiar areas if you’ve been following along the last three seasons: Oxytocin, Amygdala (of course) but also getting into large-scale brain networks that will impact our reward center (so nucleus accumbens, ventral tagmental area) and decision making (so prefrontal cortex, dorsal lateral prefrontal cortex) but also perhaps some unexpected items such as testosterone
What real-world applications or case studies exist that show these theories in action?
Laine: According to research done by Zac, companies with high trust had employees who reported “106% more energy and were 76% more engaged at work”, were “50% more productive” and employees were 50% more likely to stay with the company and 88% more likely to recommend the company to others. People working in high-trust organizations also reported liking their jobs more at 60%, “70% more aligned with their companies’ purpose, and felt 66% closer to their colleagues”, specifically because they felt And a high-trust 11% more empathy”, for coworkers, depersonalized them less and”40% less burnout from their work” and felt a greater sense of accomplishment at a rate of 41%.
What practical strategies have worked in addressing this problem?
Tease for what we’ll cover at the end of the episode?
Example: Feedback loops, emotional regulation techniques, active listening.
Laine: Honestly, what is funny about this research is that you have to trust that trust pays off.
3. Brain Mapping (Deep Dive)
Laine: Not only are some areas we have covered before familiar but so are some similar concepts. For example, trust requires the ability to have ‘theory of mind’, do self-regulation, be able to ‘mentalize’ or understand the perception of others, process emotions, and engage in empathy. However, we need to do all of this while also navigating fear and distrust. Specifically, areas that will impact our lower, less evolved, and less intelligent parts of us.
Schipper and Petermann state that the amygdala, the ventral striatum Mid brain, and the orbitofrontal cortex (behind your eyes) are active in processing thoughts and emotions, as well as determining motivation. They state the “left prefrontal, right parietal, and anterior and posterior cingulate cortices” (fingers wrapped around your thumb) are involved in that they help us understand the social environment and other peoples engagement in it.
Oxytocin in this is huge - honestly not only for trust but also for mistrust. As we know, oxytocin has a darker side and this shows up. Testerone will also lower trust but vasopressin can increase it.
Multiple studies have been done on oxytocin - both in the natural environment and what we found in participants' blood, but also by introducing lab-made oxytocin into the body and watching an increase of trust in study participants. Specifically, Zac studies show “Oxytocin appeared to do just one thing—reduce the fear of trusting a stranger.”
Testeraone is different - specifically higher levels of everyone increase social vigilance and competition, which damages trust. Schipper and Petermann state “Testosterone downregulates interpersonal trust in an adaptive manner.”.
Zac also pointed out a key factor to oxytocin - which is that stress will reduce the amount of oxytocin in the body as it is a “potent oxytocin inhibitor”. No great surprise there, most of us don’t interact with others as well when we are stressed out. And yet, how many of us work in high-performing, highly stressful environments? How much are we focused on fear instead of trust and what does this do not only to our long-term health but also the long term health of the company or team?
It should be no surprise that much like in the episodes on pleasure and addiction, we are also looking at activation in the ventral tegmental area and nucleus accumbens because we are looking at rewards and enjoyment.
In addition, Krueger and Mery-Linderberg key regions anchored in “domaingeneral large-scale brain networks: reward network (RWN), salience network (SAN),central-executive network (CEN), and default-mode network (DMN).”. Specifically, we have networks (so areas of the brain that work together well” that help anticipate rewards, anticipate treachery, identify strategies, and evaluate relationships. Speciifcally “meso-dopaminergic pathways are commonly involved in forming anticipation of reward to forecast positive and negative consequences of available options for guiding adaptive social behavior under uncertainty”. To help with this our ventral striatum and amygdala work to try to figure out reward versus risk.
Krueger et al. (2007) found that “the paracingulate cortex is critically involved in building a trust relationship by inferring another person’s intentions to predict subsequent behavior” Which is very interesting as this is a more recently evolved area of the brain and is seen to help by interacting “with more primitive neural systems in maintaining conditional and unconditional trust in a partnership.”.
Tzieropoulos also found Neuroimaging results that showed that the caudate nucleus (part of the dorsal striatum) is active specifically when we are working with reputation or expectation. So trust will change as we learn more about a person and feel we can anticipate their actions better, and this part of your brain helps in this. Phan, Sripada, Angstadt, & McCabe argues that the “ ventral striatum and the orbitofrontal cortex, both parts of the reward network, were also reported to be more active when receiving positive feedback with greater activation in consistency verse inconsistency.
It's important to note that reputation can help or harm us. The more we believe in someone’s reputation, the more we trust them, even when there starts to be evidence to the contrary. It turns out humans really don’t like being wrong. Specifically “the effect of reputation was stronger than the learning mechanism based on actual feedback”.
Tzieropoulos also reports “Neuroimaging results showed that this decrease in trust correlated with higher activation in the amygdala, caudate nucleus, midbrain regions, insula, and postcentral gyrus, consistent with the hypothesis that OT diminishes the fear of betrayal.”
4. Practical Application (Strategies & Takeaways)
Laine: Trust is the heart of what makes humans work. As we have stated before, humans are what we are because we are social creatures. Alone we are prey. Together we can travel to the moon. It is only in relation with others that we can do the most incredible things. And to do that, our nervous system has to be regulated enough so that we are functioning at our highest capability. We need to be able to access the highest parts of our intelligence, our creativity, and our ability to be flexible and react. We can only do that if we are regulated. We are only regulated when we feel safe. We only feel safe when there is trust. A simple practicel application in this is that you have to trust in trust.
In business, in relationships, in risk-taking - fear is often the killer. How often do we operate in fear? We fear things going wrong, getting hurt, and losing what we feel we can lose. So we act in fear. We stress about things going wrong. We try to put in punitive or fearful measures.
When we act in fear - we cause the pain we are trying to avoid.
Tzieropoulos found that simple things will impact how much we want to trust someone such as happy faces versus neutral or angry faces. Also found that race impacts this as well. As we remember from season 1, episode 5, race impacts our brains regardless of how we feel about people of different races. amygdala activation—scaled to the amount invested—was higher when interacting with black versus white people, independently of the overall racial bias.”Our brain is inherently racist and this shows up in Electrophysiological reactions, specifically, we get more worried when we trust someone who is not someone we see as part of our tribe. This is true for any minority group, up and including to gender. However, though women are trusted less, they are more likely to invest in people more and ‘trust’ others. “. And some disappointing but not surprising, we trust people found to be more conventionally attractive than those who were not. But we also find people who are seen as ‘real’ to be more trustworthy. They also reported individuals “ living in a racially mixed society with high-income variability”...so…America.
The question is - how do we manage fear? Fear is a natural part of the brain, but like all things, does not exist in a vacuum. We are more or less susceptible to it based on past harm, past trauma, past experiences. Siegal states ‘‘Human connections create neuronal connections’’ and states ‘‘the brain [is] the social organ of the body’’. As we continue to say - it's not nurture or nature, it’s both. Siegel & Hartzel state ‘‘Experience shapes the brain throughout life by altering the connections among neurons. . . . Experience is biology’’. Cozolino also argues this by stating ‘‘The brain is an organ of adaptation that builds its structures through interactions with others. . . . There are no single brains ’’ and ‘‘The individual neuron or single human brain does not exist in nature. Without mutually stimulating interactions, people and neurons wither and die’’. But importantly LeDoux states ‘‘Human defensive behavior clearly seems to have a long evolutionary history’’. As we have covered, we exist for survival or connection - not both - not at the same time. We connect and trust and think intelligently or creatively, or we get activated and want to fight and protect, which takes us out of intelligence and creativity. And this doesn’t exist in one relationship - it is a by-product of all of our experiences and relationships. If we have been harmed, if we have been hurt, we struggle to trust, to connect to think creatively.
So what do we do about it? Personally? In business? In teams?
Honestly part of this is the time to work on our own reactivity. To be mindful, to do the work to regulate that damned amygdala. To learn how to be angry and healthy and not react out of fear. Building up our orbitofrontal cortex which helps to be the brain’s emotion regulation system and ‘‘chief executive officer’’ as according to Siegel. “The OFC calms down the amygdala and helps us make choices in keeping with our goals and values; it allows us to choose the high road. The OFC is active in processes of self-awareness, response flexibility, regulation of emotion, and empathy or ‘‘mindsight’’. This is key to neuroplasticity.
5. Closing & Recap
In this episode, we explored how trust operates in your brain - from the oxytocin that helps you connect, to the stress that makes trust impossible, to the deep evolutionary wiring that drives your trust decisions. We learned that trust isn't just a feeling or choice - it's a biological process shaped by every relationship and experience you've ever had.
Honestly, I will say - part of this is at the heart of this season. We don’t have enough data on this because humans don’t exist in a vacuum, we exist in relations. Neuroscience is just starting to see that - and though we know trust is important, we don’t study it in relation enough. “ A first step towards a change in the definition of trust was already done by showing that trust and distrust may be distinct constructs that span different brain areas.”
A hard truth about humans is that we are honestly often unaware that we are even having an emotion until after the fact”. We feel emotions in our body, and eventually our brain kicks in and wonders why we are so tense. This is an important piece “ Neuroscientists differentiate between emotions and feelings. Emotions are considered evolutionary adaptations, nonconscious, and embodied” and feelings are awareness of this nonconscious experience but our body is letting us know how we feel and then humans try to make sense of this. “we may be driven by our emotions but unable to name our feelings.”
This makes trust complicated. We may trust or not trust someone and not know why and try to rationalize or make sense of it. But our body responds to them due to a lifetime of coding and some of that we are less conscious of. We let our past experiences, and our past traumas rule us.
And this is helpful in some things. We have evolutionary responses to keep us safe - as discussed in our very first episode when you are walking in the woods and you see a stick, you often jump - because if you jump and it's just a stick - you stay alive but if you don’t jump and it's a snake that might not be true. While this is true for a snake and a stick - it's a very different experience in human relations - yet our brain does not think so. We are so wired for protection - we would rather jump than trust.
How valuable is trust - incredibly so. And yet we suck at it. Because the heart of it is how vulnerable can you be? What is your risk distress tolerance?
“The downside of empathy and resonance is that we can drive each other into states of dysregulation quickly, and beneath awareness.”.
Gottman who is a known couples psychologist talks about this in romantic relations and states our regulation works for good or for harm. Mirroring neurons can help to regulate or activate. He states “When a wife raises conflictual issues, the husband’s heart rate may escalate, flooding him physiologically; he then shuts down or stonewalls, leaving the wife with a highly distressed heart rate. Similarly, emotionally dysregulated parents communicate their distress to their children even if there is no explicit discussion, and even if parents deny that they are upset”. We are not empathetic when we are agitated. We have such strong potential as humans, and in reality, but our safety will override this, and do us harm.
What are the takeaways? The quick one is that trust matters, but you have to trust that it matters to have it override your need to protect and be safe.
How can we help this - in all things takes time to regulate. When trust is broken, before responding in activation, make sure that you have an investment in all parties to regulate and then process. Whether it is professional, romantic, family, and especially children - take time to make sure you are in the best frame of mind instead of reacting out of fear and hurt. That helps the problem be able to be external and when we do this we create conflict that is relationship-building instead of relationship-harming.
Mindfulness is also important - for more information on this see Season 1 where we cover this in two episodes. We are all carrying around past harm and hurt from childhood throughout our lives without work. Mindfulness is a way to learn to attune and attach to ourselves, and when we find value, worth, connection, and support in ourselves, we will find we have a lot more to give others.
