Short answers, pulled from the story.
Trust in social science is the belief that another person will do what is expected, built through repeated consistency. It involves a willingness to become vulnerable to another party on the presumption that the party will act in ways that are beneficial. Scholars distinguish between generalized trust, extended to a broad circle of strangers, and particularized trust, which is specific to a situation or relationship.
Psychoanalyst Erik Erikson identified the development of basic trust as the first stage of psychosocial development, occurring during the first two years of life. Success produces feelings of security and optimism; failure leads to insecurity, mistrust, and possibly attachment disorders.
Trust acts as an economic lubricant, reducing the cost of transactions, enabling new forms of cooperation, and expanding employment, wages, and profit. Without trust, transactions like the "Market for Lemons" described by George Akerlof fail even when both parties could benefit. The World Economic Forums of 2022 and 2024 both adopted the rebuilding of trust as their central themes.
Philosopher Annette Baier argued that trust can be betrayed, whereas reliance can only be disappointed. We rely on a clock to give the time but do not feel betrayed when it breaks; by contrast, when a trusted person acts against our interests, we feel betrayal. Philosopher Lagerspetz agrees that trust is a form of reliance but insists it is not merely reliance.
A meta-analysis of 87 studies published in the Annual Review of Political Science found a consistent but modest negative relationship between ethnic diversity and social trust. The negative effect was strongest on neighbor trust, in-group trust, and generalized trust, with little significant impact on out-group trust. The authors cautioned that the effect size is modest and that claims about a severe threat to social cohesion are exaggerated.
Affective trust, proposed by Karen Jones, is an emotional optimism that the trustee will do right by the trustor. Predictive trust, contrasted by Paul Faulkner, is confidence based solely on a consistent pattern of past behavior, such as expecting a friend to be late because she has always been late. Predictive trust warrants only disappointment if the prediction proves wrong, not a sense of betrayal.