Defense mechanism
Idealization and devaluation
Someone is seen as perfect, or as worthless, with little in between.
Idealization makes a person, a place or a cause flawless and special; devaluation strips them of any worth. The two belong together. When an idealized person disappoints, they often fall all the way to the other end, because nothing in between was ever allowed.
Underneath there is usually a need for safety and self-worth. Being close to someone perfect can feel protective, and seeing others as worthless can quiet shame or envy. The two can also be divided between people: others are seen as better and stronger and oneself as lesser, a quieter form that does not swing. Everyone idealizes to some degree, and falling in love is the familiar case. It works as a defense when the picture has to be kept up at any cost.
Lena describes her new friend as the most brilliant person she has ever met and quotes her everywhere. When the friend forgets her birthday, Lena decides the friend was shallow all along and never really that clever. A few months later, Lena says the same glowing things about someone else.
When it helps
Idealization brings hope, admiration and the courage to commit, and it lets people learn from those they look up to. Devaluation, in small doses, makes it easier to let go of something that has failed.
What it can cost
Relationships tend to run in cycles of excitement and disappointment, because real people cannot match an ideal for long. The same swing can turn inward: when one's own worth moves between special and worthless, ordinary mistakes become hard to bear.
How it differs
Splitting is the wider pattern behind both: the world is divided into all good and all bad. Idealization and devaluation are that division aimed at one person: first all good, then all bad.
In McWilliams' model
McWilliams counts it among the primary defenses. These deal with the border between the self and the outside world, and they shape experience as a whole: what is felt, what is seen, and whose feeling is whose.
Character styles that lean on it
Everyone uses defenses, every day, and noticing one in oneself does not mean that something is wrong. This page describes a general way of coping, not a diagnosis. If something described here is frequent, distressing, or gets in the way of daily life, it is worth discussing with a doctor or a mental health professional.