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

Touching helps build the sexual brain

September 21, 2017
Hormones or sexual experience? Which of these is crucial for the onset of puberty? It seems that when rats are touched on their genitals, their brain changes and puberty accelerates. In a new study publishing September 21 ...

Gene immunotherapy protects against multiple sclerosis in mice

September 21, 2017
A potent and long-lasting gene immunotherapy approach prevents and reverses symptoms of multiple sclerosis in mice, according to a study published September 21st in the journal Molecular Therapy. Multiple sclerosis is an ...

Neuron types in brain are defined by gene activity shaping their communication patterns

September 21, 2017
In a major step forward in research, scientists at Cold Spring Harbor Laboratory (CSHL) today publish in Cell a discovery about the molecular-genetic basis of neuronal cell types. Neurons are the basic building blocks that ...

Your neurons register familiar faces, whether you notice them or not

September 21, 2017
When people see an image of a person they recognize—the famous tennis player Roger Federer or actress Halle Berry, for instance—particular cells light up in the brain. Now, researchers reporting in Current Biology on ...

Highly precise wiring in the cerebral cortex

September 21, 2017
Our brains house extremely complex neuronal circuits whose detailed structures are still largely unknown. This is especially true for the cerebral cortex of mammals, where, among other things, vision, thoughts or spatial ...

Faulty cell signaling derails cerebral cortex development, could it lead to autism?

September 20, 2017
As the embryonic brain develops, an incredibly complex cascade of cellular events occur, starting with progenitors - the originating cells that generate neurons and spur proper cortex development. If this cascade malfunctions ...

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.