Title: "Animal spirits" and hormones: understanding trust in interpersonal interactions
Funder: Economic and Social Research Council

Abstract: Prosperity in all aspects of social life, from interpersonal relationships to economic or political relationships, depends on human cooperation and trust. The concept of trust is particularly relevant these days, as some economists have attributed the ebbs and flows of the economy to irrational fluctuations in our confidence in others. Trust will be defined as the subjective expectation that others will not harm or disadvantage us in instances when they have an opportunity to do so. Accordingly, trust decisions will be defined as the decisions that give others such an opportunity. Why do people differ in the ways and degrees in which they trust familiar or unfamiliar others in given interpersonal situations? What dynamic interplay of parameters determines trust decisions in interpersonal interactions? Can such decisions be facilitated or inhibited by some intervention and how? These questions are at the heart of this project. To answer these questions we will design experiments that entail 'on-line' interpersonal exchanges and will model the complexity of human behaviour in these interactions using advanced methods. We will measure the dynamic influence of various individual traits and social signals (e.g. 'trustworthy' behaviour by others) on people's decisions to trust others. In this endeavour, we will use the oxytocin system as a tool. The oxytocin system in the brain may be one of the main mechanisms driving individual differences in the expression of interpersonal trust. In animal studies, scientists have discovered that this neural system, which uses the hormone oxytocin to communicate with other brain areas, plays a key role in inter-species differences in social behaviour, as well as in differences between members of the same species. For example, the oxytocin system has been shown to influence the formation of lasting attachments with one's offspring or peers, the display of caring behaviour towards offspring or partners, social play, the recognition of one's partner's or offspring's by their odour, or the display of distress by offspring when abandoned. While there is also accumulating evidence that the function of the oxytocin system also influences social behaviour in humans, almost nothing is known regarding how the oxytocin system is organised in the human brain. We also know next to nothing about the possible existence of gender differences (as is the case with other species), about how this system is linked with differences in human social preferences, including decisions to trust, and about how this system can exert a dynamic influence on the processes underlying judgements of trustworthiness and decisions to trust. In this project, we will use state-of-the-art neuroimaging techniques and innovative data modelling and analysis methods to try and shed some light on these questions. We hope to generate new findings that will make a significant contribution to understanding the processes driving trust behaviour, as well as to generate new evidence about the oxytocin system in the human brain, which will be of direct interest across a range of disciplines.


Research activity codes: 1.1 NORMAL BIOLOGICAL DEVELOPMENT AND FUNCTIONING;1.2 PSYCHOLOGICAL AND SOCIOECONOMIC PROCESSES
Health categories: MENTAL HEALTH;NEUROLOGICAL