Once we have an idea of what culturally sustainable robotic behaviour looks like, we face the problem of how to get a robot to actually behave as such. We argue that for a robot to exhibit behaviour that conforms to the cultural values of the human environment they operate in; they must be equipped with the capability to mindread. Our argument follows from the observation that cultural norms can only be correctly applied when certain conditions are met, and that those conditions can refer to the internal states of the agents taking part in the interaction. Consequently, for an artificial agent to correctly apply a cultural norm, it must infer the internal states of other agents. If a cultural norm is incorrectly applied, then a human agent could consider the resulting behaviour inappropriate. This renders mindreading essential to produce behaviour that respects cultural expectations.