Researchers shed light on why people trust

August 11, 2015
Credit: Rice University

Trust matters whether it's love, money or another part of our everyday lives that requires risk, and a new study by a Dartmouth brain researcher and his collaborators sheds light on what motivates people to make that leap of faith.

The findings appear in The Journal of Neuroscience.

Collaboration is essential to human life, fostering that are intrinsically rewarding, fulfill a basic social need to belong and promote positive physical and mental health. One critical aspect of collaboration is trust, or assuming mutual risk with a partner.

In the new study, participants thought they were playing an economic investment game with a close friend, a stranger or a slot machine. In reality, they were playing with a simple algorithm that reciprocated trust 50 percent of the time. The researchers developed a computational model that predicted each player's decision for each round given their previous experiences in the game.

Results showed that participants found positive interactions with a close friend more rewarding than interactions with a stranger or , and that the researchers' "social value" model predicted participants' investment decisions better than models that only considered financial payoffs. Neuroimaging also showed that specific brain signals—in the and medial prefrontal cortex—correlated with social value signals when the participants made their decisions.

The ventral striatum is a key pathway in reward processing, while the is associated with representing another person's mental state. Together, these regions provide additional evidence that players receive a greater social reward signal when they learn their friend reciprocated than the other two players in the game. This occurs despite participants learning that each player is only reciprocating 50 percent of the time. But because players receive this additional reward signal, they end up trusting their friend more than the other players throughout the game.

"These findings show the importance of social relationships in how we make everyday decisions and specifically how relationships can change our perceived value associated with a given decision," says co-author Luke Chang, an assistant professor in Psychological and Brain Sciences at Dartmouth. "This is a very important finding as most macroeconomic models of individual decision-making are based solely on financial rewards and strongly influence policy decisions. Our findings also provide a new method to test computational models using brain imaging data, which might be useful for studying amorphous concepts such as trust and reciprocity."

Explore further: Character traits outweigh material benefits in assessing value others bring us

More information: Computational Substrates of Social Value in Interpersonal Collaboration, The Journal of Neuroscience, May 27, 2015. 35(21):8170 – 8180. cosanlab.com/static/papers/Far … rietal2015JNeuro.pdf

Related Stories

Character traits outweigh material benefits in assessing value others bring us

August 3, 2015
When it comes to making decisions involving others, the impression we have of their character weighs more heavily than do our assessments of how they can benefit us, a team of New York University researchers has found.

Altruism is simpler than we thought, brain study shows

July 15, 2015
A new computational model of how the brain makes altruistic choices is able to predict when a person will act generously in a scenario involving the sacrifice of money. The work, led by California Institute of Technology ...

What is more rewarding: A soccer goal or prize money?

April 15, 2015
Soccer fans hold their breath in situations like these: Two players on a team are in front of the opponent's goal with the attacking player having to make an important decision: Is it better to pass the ball to the teammate ...

Sense of obligation leads to trusting strangers, study says

May 15, 2014
Trusting a stranger may have more to do with feeling morally obligated to show respect for someone else's character than actually believing the person is trustworthy, according to new research published by the American Psychological ...

Recommended for you

New research suggests high-intensity exercise boosts memory

November 22, 2017
The health advantages of high-intensity exercise are widely known but new research from McMaster University points to another major benefit: better memory.

To forget or to remember? Memory depends on subtle brain signals, scientists find

November 22, 2017
The fragrance of hot pumpkin pie can bring back pleasant memories of holidays past, while the scent of an antiseptic hospital room may cause a shudder. The power of odors to activate memories both pleasing and aversive exists ...

Pitch imperfect? How the brain decodes pitch may improve cochlear implants

November 22, 2017
Picture yourself with a friend in a crowded restaurant. The din of other diners, the clattering of dishes, the muffled notes of background music, the voice of your friend, not to mention your own – all compete for your ...

What if consciousness is not what drives the human mind?

November 22, 2017
Everyone knows what it feels like to have consciousness: it's that self-evident sense of personal awareness, which gives us a feeling of ownership and control over the thoughts, emotions and experiences that we have every ...

Now you like it, now you don't: Brain stimulation can change how much we enjoy and value music

November 20, 2017
Enjoyment of music is considered a subjective experience; what one person finds gratifying, another may find irritating. Music theorists have long emphasized that although musical taste is relative, our enjoyment of music, ...

MRI uncovers brain abnormalities in people with depression and anxiety

November 20, 2017
Researchers using MRI have discovered a common pattern of structural abnormalities in the brains of people with depression and social anxiety, according to a study presented being next week at the annual meeting of the Radiological ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.