The hypothesis of the article* is based on the observation that a psychological impression is insufficient to explain why there is some similarity between humans and animals. It is not a direct relation like similarity commonly given as an example: between parents and children. Though, a source generating this aesthetic illusion, no matter how realistically, must be located somewhere else. First, I associate it with the pre-evolutionary materials: in physiognomy developed especially in the 18th century and somehow anticipating Darwin’s main assumptions in The Expression of the Emotions in Man and Animals. Then, I analyze how Darwin was included in the popular aesthetic narrative, and how the notion of similarity between humans and animals was developed with Darwin’s input, providing particular consequences—relevant until today—like animal anthropomorphisation.