Do we inherit our trusting disposition?

Where does distrust come from? Why do we distrust certain people as soon as we meet them? And is this in our genes?

Questions such as these which social scientists have been asking for a while to understand the disposition of distrust – as an increasing consensus is emerging that distrust is not the opposite of trust.

Although both trust and distrust are strongly influenced by the individual’s environment, trust seems to be highly influenced by genetics whereas distrust is not.

Research analysis estimated that 30 per cent of trust was due to genetic influences, while distrust was not heritable.

In this study, scientists examined the question of distrust and genetic involvement by studying two sets of twins: Those who have identical genetic relatedness or identical twins and, adult fraternal or non-identical, twins- those who have different genetic relatedness.

324 identical and 210 fraternal twins participated in a study task which asked them to decide how much money to send to another participant thus representing trust. In another task they were asked to decide how much money to take away from a participant which represents distrust.

According to the principles of behavioural genetics, identical twins should behave more similarly to each other as they share their genes compared to fraternal twins as their genes are imperfectly correlated.

The researchers found that identical twins behaved similarly in trust behaviours but not in distrust behaviours suggesting that trust is associated with their genes, but not distrust.

Research analysis estimated that 30 per cent of trust was due to genetic influences, while distrust was not heritable. Shared environment (common experiences of growing up in the same family and interacting with the same immediate peers) contributed to 19 per cent of distrust, while shared environment did not contribute to trust at all.

Unshared experiences (the siblings’ unique experiences in life) had the biggest impact on both trust and distrust. 81 per cent of distrust was contributed by unshared experiences and 70 percent to trust.

This shows that neither most of a person’s propensity to trust or distrust is inherited or commonly socialised but instead is influenced by a person’s unique life experiences.

However the disposition to trust is not only because of our unique experiences but is also influenced by genetics in a significant way whereas, distrust has no such genetic influence.

It seems that our trusting disposition is inherited from our parents and ancestors but when we distrust someone or something then it seems to be ingrained in us due to our past experiences or nurtured by our families and immediate peers.

Source: Proceedings of the National Academy of Sciences