Why Trust is Good for your Health

In the latest in a series of blog pieces examining the correlation between social capital and health, Martin Ljunge explores the relationship between trust and health.

To support the work by cities and communities to improve quality of life, researchers attempt to carefully trace the correlations of investments in social capital to measurable benefits. Ultimately the goal is to show these relations to be causal. New research on these issues is  examined in the newly published Elgar Companion to Social Capital and Health. It includes an innovative approach by Martin Ljunge in the article, “Trust Promotes Health: Addressing Reverse Causality By Studying Children of Immigrants” (chapter available Open Access on Elgaronline).

Does trust result in better health?

If you ask people about their trust and health, it is likely that those expressing high trust also are feeling healthy. Can we conclude that trust caused their well-being? It is of course possible but it could also be that those who are in good health express high trust because life has gone well for them. Similarly, those with poor health may express suspicion toward people in general. To understand if trust leads to well-being, we must go beyond studying correlations among individuals as they may measure causal effects in both directions.

We recognise that trust is a subjective measure, influenced by the social environment. Trust is commonly defined as the individual’s response to the survey question: “Generally speaking, would you say that most people can be trusted or that you need to be very careful in dealing with people?” The author finds a person’s level of trust that is independent of the present day social influences by taking it from that person’s birth country before their immigration to the adopted country. This approach also eliminates the possibility of including some reverse causality, because present day health cannot influence past trust in the ancestral country. He then focuses on the woman who immigrates and becomes a mother in her adopted country. By comparing her trust with that of her children’s trust advantages and then with her children’s health, he reasons that his experimental design provides a valid causality test: Does trust cause better health? The key here is that the mother’s trust, measured in her birth country, is exogenous to her child’s present health, who lives in a different country.

In his article, Martin Ljunge demonstrates that values, trust in particular, are primarily communicated by the mother. He then applies large data sets to estimate the mother’s trust level in her birth country, which he takes to be the average trust level in that country before her immigration. These large data sets include the European Values Survey and the World Values Survey.

He shows graphically that a high level of her trust gives an advantage to her children’s trust. But more critically, it also gives her offspring an advantage in health, a result he demonstrates with multivariate regression analysis including a selection of variables that he chose to see if they conflict with the results he focuses on. These control variables include demographics, education, work, marital status, and high or medium income.

Professor Ljunge’s paper tackles the difficult problem we face when one attempts to establish that social capital, in this case its element of trust, promotes health. In this design we need an exogenous measure of trust. His paper provides an innovative approach to achieve this, which yields more credible evidence on the health benefits of trust.

Professor Martin Ljunge is a Swedish health economist who trained at the University of Chicago.

Read Martin Ljunge’s chapter Trust promotes health: addressing reverse causality by studying children of immigrants free on Elgaronline for a limited time

Elgar Companion to Social Capital and Health edited by Sherman Folland and Eric Nauenberg is out now.

Related articles: The Importance of being Social –Sherman Folland investigates the influential role social capital plays in mental health and physical wellbeing.