by If an annoyed stranger knocked on your door trying to use your phone, would you? How about lending them a fiver for the bus, if they assured you they would return and pay you back? In today’s broken world, trust seems to be lacking and divisions run deep. Many people find it difficult to trust strangers, perhaps especially those who are different from us.
But why? Recent advances by our international team of researchers, published in Scientific Reports, have shed light on the genetic basis of trust. We discovered that our ability to trust strangers may not be just a social or psychological trait – it may be rooted in our DNA.
This is important, because it turns out that confident people may live longer and healthier lives compared to their more skeptical counterparts.
Research has shown that people who trust strangers have a significantly lower risk of cardiovascular disease, even after factors such as smoking, age and biological sex are taken into account. But it is impossible to understand why this is so.
For many years, the study of trust has been an area of the social and political sciences, viewed primarily as a societal construct. Two main theories have emerged to explain why some people are more confident than others. One suggests that confidence is a stable trait shaped by early life experiences.
The other argues that it is influenced by a person’s constant 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?” depending on whether you were robbed the day before, or your stolen wallet was returned.
This is where my research comes in. I currently head the Genetic and Molecular Epidemiology unit at Lund University, Sweden. For the past 15 years, I have been on a quest to discover the biological underpinnings of trust and its links to better health. My latest study, involving 33,882 blood donors from Denmark, is a significant milestone in this effort.
Armed with genetic data and information about our participants’ propensity to trust strangers, we conducted the largest genome-wide association study (studies linking traits to genes) of social trust to date. We obtained individual levels of trust from participants’ responses to customized and validated social trust questions. Our analysis identified one gene, PLPP4, that was strongly associated with the trait of trusting others.
We also found that the PLPP4 gene explained a significant 6% of the variance in social trust within the study population. That means if you take two people with similar upbringing, education and life experiences, this gene alone could account for 6% of the difference in how much they trust others.
This may seem like a small number but it is a significant 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 as an explanation for differences in body mass index among Europeans, but it only accounts for 0.34% of those differences.
Fight or flight
But what does this mean in practical terms? I believe that the discovery of the “trust gene” could act as a bridge between biology and social science, challenging the traditional division between the two fields. Furthermore, the fact that this gene is mainly expressed in the brain raises interesting questions about its role in shaping neural pathways and signaling mechanisms.
Although it is tempting to speculate that trust could be improved through the manipulation of this gene, I must be careful against such a simple interpretation. Besides directly affecting confidence levels, this gene likely plays a role in shaping circuits in the brain related to our innate “fight or flight” survival mechanism.
This system, which is hardwired into each of us, regulates our response to stress, by releasing certain hormones. Although useful in the short term, long-term exposure to stress hormones can be harmful to health – in fact it has been 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 meet new people, it makes sense that our innate tendency to trust others could have significant health benefits. In fact, if trusting others acts as a buffer against stress, reducing cortisol levels, it can reduce the risk of cardiovascular disease and depression.
The implications could be profound. However, more research is needed to unravel the complex interplay between genetics, trust and health. That said, the discovery of a genetic basis for trust opens up new avenues for interdisciplinary research, providing fresh insights into the complex connections between biology, behavior and society.
As we unravel the mystery of trust, one thing is clear: understanding its genetic roots may hold the key to building healthier, more cohesive communities in an increasingly fragmented world.
This article from The Conversation is republished under a Creative Commons license. Read the original article.
Giuseppe ‘Nick’ Giordano has received funding from the Swedish Foundation for Humanities and Social Sciences.
