The watching eyes effect describes the phenomenon that just showing simple images of watching eyes can change people’s behaviors. There is much debate about whether this effect can be explained by the reputation mechanism and the norm psychology. Furthermore, the watching eyes effect has been found to be affected by factors such as task type, experimental situation, exposure time, anonymity, participants’ group identity, and personal characteristics. Future research need to explore evolutionary mechanisms from the perspective of embodied cognition, cross-cultural variations in the watching eyes effect, and neural mechanisms underlying this effect. Researchers should also consider applying the watching eyes effect in real-life situations to increase prosociality.