by its sense of shame,' and meant to steer the charioteer away from the shameful and towards the divine. The good horse, meanwhile, 'is obedient to the charioteer' and 'still controlled. In Ancient Greek philosophy, Plato writes in Phaedrus about a speech given by Socrates that splits the soul into three parts: a 'charioteer,' or the man that participates in everyday life, a 'good horse' that knows of self-control, moderation, and shame, and a 'bad ' who 'does everything to aggravate its yokemate and its charioteer.' The bad horse, who 'barely yields to horsewhip and goad combined,' tempts the charioteer in matters of eros and lust. Domyo records good deeds, but Dosho reports bad ones. In Japanese Buddhism, the Kushoujin are a pair of beings – Domyo, meaning 'same name' and Dosho, meaning 'same birth' – which sit on a person's shoulders, observing and reporting all his deeds. The angel pushes the individual to do good and obey God while that from the jinn does the opposite. The word qarīn literally means 'constant companion'. However, there is a concept much more similar to the shoulder angel and devil: the qareen, which, according to Islamic literature, is a personal companion, and there are two with each individual, one from the angels and another from the jinn. However, these angels do not have influence over the choices one makes, and only record one's deeds. There is a similar Islamic belief of Kiraman Katibin, two angels residing on either shoulder of humans which record their good and bad deeds. Both angels and devils are often regarded as having the ability to access the person's thoughts, and introduce ideas. At the same time each person is assailed by devils, not usually considered as single and dedicated to a single person in the same way as the guardian angel, who try to tempt the person into sin.

In some Christian folklore, each person has a dedicated guardian angel whose task is to follow the person and try to prevent them from coming to harm, both physical and moral. The concept is similar to ideas of personal tutelary spirits that are very common in many ancient and traditional cultures. Hermas is told to understand both angels, but to only trust the Angel of Righteousness. These angels in turn descend into a person's heart, and attempt to guide a person's emotions. 140–150, has a reference to the idea of two angels: 'There are two angels with a man-one of righteousness, and the other of iniquity'. The non-canonical early Christian book The Shepherd of Hermas, of around A.D. In both this and Christopher Marlowe's play The Tragical History of Doctor Faustus, of about 1592, the 'Good Angel' and 'Bad Angel' offer competing advice (Act 2, scene 1, etc.) to the hero. In Western culture the idea develops the Christian concept of a personal guardian angel, who was sometimes considered to be matched by a personal devil who countered the angel's efforts, especially in popular medieval dramas like the 15th century The Castle of Perseverance.

Often, both resemble their host, though sometimes they will resemble other characters in the story who are responsible or mischievous. The shoulder devil likewise usually looks like a traditional devil with reddish skin, horns, barbed tail, a trident and in some cases, cloven hooves. The shoulder angel often uses the iconography of a traditional angel, with wings, a robe, a halo, and sometimes a harp.

Look over the shoulder cartoon