Trust Polarity: A Situational Model of Insider-Outsider Trust Switching

Existing trust models measure the magnitude of trust -- how much one party trusts another. They do not explain why the same individual trusts an outsider over a known insider in one situation, yet reverses that preference in another. This paper introduces Trust Polarity, a situational model that predicts the direction of trust: whether an individual will extend trust toward an in-group insider or an out-group outsider in a given context. The model identifies five core variables -- Dissatisfaction, Agency, Reversibility, Vulnerability, and Network Accountability -- and organizes them into two competing force terms with an asymmetric multiplicative structure. Three baseline constants (Cultural Default, Personal Burn History, and Identity Layer Activation) set the frame before the situational computation runs. The model is applied to six domains: electoral behavior, consumer transactions, healthcare trust, brand switching, hiring decisions, and investment fraud. In each domain, the equation's output correctly predicts the observed direction of trust and identifies the structural conditions under which exploitation becomes most likely.