²⁰(Herz and von Clef, 2001). It is also typical for people to value objects more if it takes a lot of effort to obtain or produce them. This can be seen as a simple heuristic to approximate the reward, but it can of course go wrong (Kruger et al., 2004). Eldar et al. (2016) further propose that mood influences perception of rewards, so that happiness makes rewards look higher, and the oppositive for a negative mood. Furthermore, individual differences are considered by Scherer (2021) in terms of “appraisal biases”, which is a mechanism explaining individual tendencies to experience particular emotions, and ultimately, affective disorders; these could presumably be interpreted in terms of different priors being used by the individuals.