Fixation (psychology)
Fixation: 'concept originated by Sigmund Freud
Sigmund Freud
Sigmund Freud , born Sigismund Schlomo Freud , was an Austrian neurologist who founded the discipline of psychoanalysis...

 (1905a) to denote the persistence of anachronistic sexual traits'. Subsequently '"Fixation" acquired a broader connotation. With the development of theory of libidinal stages...the term came to mean a persistent attachment, not only to the specific instinctual aims of a particular era, but, instead, to the entire complex of self and object relation' at that time.

More generally, it is the state in which an individual becomes obsessed with an attachment to another person, being or object (in human psychology
Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...

): 'A strong attachment to a person or thing, especially such an attachment formed in childhood or infancy and manifested in immature or neurotic behavior that persists throughout life'.
In Three Essays on the Theory of Sexuality (1905a), Freud distinguished 'fixations of preliminary sexual in the case of voyeurs from the 'after-effects of infantile incestuous fixation of his [or her] libido'.

Sigmund Freud theorized that some humans may develop psychological fixation due to:
  1. A lack of proper gratification during one of the psychosexual stages of development
    Psychosexual development
    In Freudian psychology, psychosexual development is a central element of the psychoanalytic sexual drive theory, that human beings, from birth, possess an instinctual libido that develops in five stages. Each stage — the oral, the anal, the phallic, the latent, and the genital — is characterized...

    , or
  2. Receiving a strong impression from one of these stages, in which case the person's personality would reflect that stage throughout adult life.