The World Values Survey (WVS) question on trust has been widely used to study the economic effect of trust. Recent work, however, questions its validity as an accurate measure of trust by showing that it is not correlated with the sender's behaviour in the Berg etal. trust game. What measure then should we trust to measure trust? In this article, we argue that the sender's behaviour in a trust game is driven both by beliefs and by preferences. In contrast, WVS-like measures capture mostly the belief-based component of a trust game.