Horror-of-personality is a specific sub-category of horror

Horror fiction

Horror fiction also Horror fantasy is a philosophy of literature, which is intended to, or has the capacity to frighten its readers, inducing feelings of horror and terror. It creates an eerie atmosphere. Horror can be either supernatural or non-supernatural...

 and thriller genres; as opposed to excessive violence

Violence

Violence is the use of physical force to apply a state to others contrary to their wishes. violence, while often a stand-alone issue, is often the culmination of other kinds of conflict, e.g...

 or the presence of malevolent supernatural

Supernatural

The supernatural or is that which is not subject to the laws of nature, or more figuratively, that which is said to exist above and beyond nature...

 beings, such stories evoke horror and/or suspense through villains who are perfectly human, but possess horrific personalities. They usually focus on Freud

Sigmund Freud

Sigmund Freud , born Sigismund Schlomo Freud , was an Austrian neurologist who founded the discipline of psychoanalysis...

ian psychology, as well as the cause and effect of profound insanity

Insanity

Insanity, craziness or madness is a spectrum of behaviors characterized by certain abnormal mental or behavioral patterns. Insanity may manifest as violations of societal norms, including becoming a danger to themselves and others, though not all such acts are considered insanity...

. Each narrative will either document an unbalanced person's descent into madness, or else follow somebody on the trail of a murderous psychopath. The settings are often deceptively ordinary, such as cheerful suburban homes or shabby hotels.

Examples include the stories of Patricia Highsmith

Patricia Highsmith

Patricia Highsmith was an American novelist and short-story writer most widely known for her psychological thrillers, which led to more than two dozen film adaptations. Her first novel, Strangers on a Train, has been adapted for stage and screen numerous times, notably by Alfred Hitchcock in 1951...

 and Edgar Allan Poe

Edgar Allan Poe

Edgar Allan Poe was an American author, poet, editor and literary critic, considered part of the American Romantic Movement. Best known for his tales of mystery and the macabre, Poe was one of the earliest American practitioners of the short story and is considered the inventor of the detective...

, as well as classic films like Psycho

Psycho (1960 film)

Psycho is a 1960 American suspense/psychological horror film directed by Alfred Hitchcock and starring Janet Leigh and Anthony Perkins. The film is based on the screenplay by Joseph Stefano, who adapted it from the 1959 novel of the same name by Robert Bloch...

and What Ever Happened to Baby Jane?

What Ever Happened to Baby Jane? (film)

What Ever Happened to Baby Jane? is a 1962 American psychological thriller film produced and directed by Robert Aldrich, starring Bette Davis and Joan Crawford. The screenplay by Lukas Heller is based on the novel of the same name by Henry Farrell...

.