Defence mechanisms in plain words

What the term means

A defence mechanism is a mental habit that protects you from something that would be too painful, shameful or threatening to hold in mind. Psychoanalytic writers describe them as largely unconscious. You do not decide to use one; you notice afterwards that a subject slid away, or that you were suddenly sure it was someone else's fault.

The concept is old and sprawling. Different authors list different mechanisms and group them differently. This article follows the most used scheme: George Vaillant's four levels, and the seven-level Defense Mechanism Rating Scales (DMRS) that researchers later built.

Nine of them, as types of situation

Placement follows Vaillant's hierarchy as summarised on the Wikipedia article on defence mechanisms, and the DMRS levels as given by Di Giuseppe and Perry (2021). The sources differ on some entries, which is part of the point of the last section.

The two rankings

Vaillant's hierarchy. Vaillant, Bond and Vaillant (1986) followed 307 men for 40 years, in what began as a study of Harvard students. A rater who interviewed each man at age 47 scored how mature his defences were. Defence maturity correlated strongly with independent measures of outcome and appeared to be a separate dimension of mental health. The four levels run from pathological (delusional projection, denial, distortion) through immature (acting out, projection, splitting) and neurotic (displacement, dissociation, intellectualisation, isolation of affect, reaction formation, repression) to mature (altruism, anticipation, humour, sublimation, suppression).

The DMRS. Researchers working from Vaillant's idea built the Defense Mechanism Rating Scales. They list 30 defences in seven levels, from action defences like acting out at the bottom to the high-adaptive level (affiliation, humour, sublimation, self-observation) at the top. Trained raters score them from recorded sessions or interviews.

DSM-IV (1994) included a provisional axis for assessing defences, and the DMRS is reported to have inspired it. A provisional axis is a proposal, not an established part of diagnosis.

What shows up in a life

The same defence is neither good nor bad in itself. A person who suppresses an urge to snap at someone in a meeting is using a mature defence. Someone who stops feeling anything about a loss is using a costly one. What matters is the pattern: how rigid it is, what it prevents, and what it costs.

A common type of situation: you reach for the same reason, every time, why a certain conversation cannot happen yet. The reason may be true each time. The sameness is what a psychodynamic reading looks at, and a clinician would ask what the reason spares you.

What is contested

• Evidence base. Critics note that much of the support comes from clinical observation and interpretation, and that theory should be separated from observable behaviour.
• Reliability. Vaillant himself wrote that defences are hard to measure reliably, while arguing their validity makes them useful in diagnosis.
• Samples. Vaillant's hierarchy came from a long-term study of men. The 2012 therapy study by Perry and Bond followed 21 adults. Small and narrow samples limit what can be said for everyone.
• Therapy change. In that 2012 study, change in defences in the first 2.5 years of long-term dynamic therapy correlated with functioning and symptoms at five years. The authors suggest defences may mediate improvement. Correlation in 21 people does not establish it.
• Levels disagree. Vaillant's scheme has four levels; the DMRS has seven. Rationalisation and denial sit in different places. A defence's label can depend on whose list you use.
• Rating the inner life. The authors of the DMRS-Q, a computerised sorting version of the scales, describe its validation as preliminary.

None of this makes the idea useless. It means defence mechanisms are a vocabulary for patterns, held loosely, and should not be used as a verdict on a person.

Using the idea on yourself, carefully

The vocabulary is most useful as a question, not as a label. If you notice a habit, such as joking when a conversation turns serious, you can ask three things: what does this spare me, when did I first need it, and what does it cost me now? Those questions do not need the word "reaction formation" or "intellectualisation". The word comes second, as a handle if it helps.

Be slow to apply a mechanism to someone else. Telling a partner they are "projecting" is nearly always an accusation, and the term was built for use inside a patient's own work, with a clinician who can be wrong in the open.

Where TwentyThird fits

TwentyThird reads what members write for recurring moves: a subject changed, a reason repeated, a feeling turned into an argument. Oneli names these in plain words, as questions rather than diagnoses. It does not rate your defences or place you on a level. See how Oneli works and the evidence we cite.

What this does not replace

A word like "projection" is easy to apply to other people and hard to apply to yourself. A therapist can tell you which, if any, fits, and what it protects. A list in an article cannot. If you are in danger, contact local emergency services now. In the EU, call 112.