Would you consent if a distressed stranger knocked on your door and wanted to use your phone? How about loaning them a fiver for the bus if they assure you they’ll come back and pay it back? In today’s fragmented world, trust seems elusive and divisions run deep. Many people have a hard time trusting strangers, especially those who are different from us.
But why? The latest discovery, published in Scientific Reports by our international team of researchers, has shed light on the genetic basis of trust. We discovered that our ability to trust strangers may be more than a social or psychological trait, it may stem from our DNA.
This is important because it turns out that trusting people may actually live longer, healthier lives compared to their more skeptical counterparts.
Studies have shown that those who trust strangers have a significantly lower risk of cardiovascular disease, even when factors such as smoking, age and biological sex are taken into account. But it is still difficult to understand why this is the case.
For decades, studies on trust have been the field of social and political sciences and have been seen primarily as a social structure. Two main theories have emerged to explain why some people trust more than others. One of these suggests that trust is a stable trait shaped by early life experiences.
The other suggests that it is influenced by the person’s ongoing evaluation of the social environment. I can easily imagine the answer to the standard social trust question: “Would you say that most people can be trusted, or that you can’t be too careful when dealing with people?” This will depend on whether you were robbed the day before or whether your dropped wallet was returned.
This is where my research comes into play. I currently lead the Genetics and Molecular Epidemiology unit at Lund University in Sweden. For the last 15 years I have been on a quest to uncover the biological underpinnings of trust and its links to better health. My latest study involving 33,882 Danish blood donors marks an important milestone in this effort.
With genetic data and information about our participants’ propensity to trust strangers, we conducted the largest genome-wide association study of social trust to date (studies that link traits to genes). We obtained individual trust levels from participants’ responses to specific and validated social trust questions. Our analyzes identified a single gene, PLPP4, that is strongly associated with the trait of trusting others.
We also discovered that the PLPP4 gene significantly explained 6% of the variation in social trust in the study population. This means that if you take two people with similar upbringing, education, and life experiences, this gene alone could explain 6% of the difference in how much they trust others.
This may seem like a small number, but it is an important finding in the field of genetics, especially when considering the complexity of human behavior. To put this into context, a gene called “FTO” is often cited to explain body mass index differences between Europeans, but this gene only accounts for 0.34% of these differences.
fight or flight
So what does this mean in practical terms? I believe that the discovery of the “trust gene” could serve as a bridge between biology and social sciences and challenge traditional distinctions between the two fields. Moreover, this gene is expressed predominantly in the brain, raising intriguing questions about its role in shaping neural pathways and signaling mechanisms.
While it is tempting to speculate that manipulating this gene might increase trust, I need to be wary of such simplistic interpretations. Rather than directly affecting levels of trust, this gene may play a role in shaping circuits in the brain associated with our innate “fight or flight” survival mechanism.
This system, built into each of us, governs our response to stress through the release of certain hormones. Although beneficial in the short term, long-term exposure to stress hormones can be detrimental to health; It is actually linked to cardiovascular problems, anxiety and depression.
We suspect that the PLPP4 gene may somehow moderate the fight-or-flight mechanism. And if our fight-or-flight system is less intense when we encounter new people, it makes sense that having an innate tendency to trust others could have important health benefits. Indeed, the fact that trusting others acts as a buffer against stress and therefore reduces cortisol levels may reduce the risk of cardiovascular disease and depression.
The effects can be profound. But more research is needed to unravel the complex interplay between genetics, confidence, and health. However, the discovery of the genetic basis of trust opens new avenues for interdisciplinary research, offering new insights into the complex connections between biology, behavior and society.
As we continue to unravel the mysteries of trust, one thing is clear: Understanding the genetic origins of trust may be key to fostering healthier, more harmonious communities in an increasingly fragmented world.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
Giuseppe ‘Nick’ Giordano received funding from the Swedish Foundation for the Humanities and Social Sciences.