Defence Mechanisms are certain unconscious behaviours and actions that a person automatically does to defend themselves from harmful or difficult situations, events or even thoughts.

Essentially, it is what the mind automatically does to protect itself from something that it may see as potentially damaging. In this article, we take a look at 15 common defence mechanisms – many of which people do on a daily basis. We should note that there are an almost unlimited number of defence mechanisms that exist.

Defence mechanisms are an important topic in mental health. Defence mechanisms can be both positive and negative. When they are used too much, defence mechanisms can cause psychological distress.

As a word of warning, this article does contain some topics which may cause unease or trigger issues for some. Remember that across our website, we have a wealth of help if needed.

Defence mechanisms are an automatic process of the brain


Repression is a very well-known type of defence mechanism. It refers to the process where certain harmful information arises (e.g. traumas, impulses or thoughts), but the repression defence mechanism doesn’t allow said information to enter conscious awareness.

But this doesn’t get rid of the information – instead it lies deep in the mind. The feelings aren’t dealt with, but still has the potential to influence a person’s behaviour.

An example would be a person who has repressed memories of being the victim of an attack by a dog at a young age. They may grow up to have a fear of dogs, causing them to be reluctant to leave the house out of fear of seeing a dog – even though they don’t know why they have this fear.

With this in mind, it is therefore important to examine repressed memories. Repression can be a good short-term measure, but not in the long-term. Repression is similar to another defence mechanism called ‘suppression’ – which is discussed next!


Suppression is a process where a person deliberately tries to force a memory, thought or feeling out of their mind. A person may have a traumatic memory from the past, but they do not try and process it.

An example may be a person having been the victim of a traumatic event, such as witnessing a car crash. But instead of thinking about the event, they attempt to force the memory from their conscious awareness. By doing this, they try and avoid processing it, and almost enter a state of denial about whether or not the event even happened.

The idea for the person is that by ignoring the event, they are able to continue living their life as they would do normally. This has a positive short-term effect, but it causes problems that aren’t dealt with.

It is similar to the defence mechanism “denial” – which is covered below. Suppression is rare, with repression the more common of these closely related mechanisms.


A well-known defence mechanism is displacement – where someone takes out their frustrations or anger on someone else – usually some unrelated to the cause of the frustrations.

The person may decide to launch a tirade on someone, using them or an object as a tool to take out their frustrations. But they are normally careful not to do so to someone in power. Instead they target someone they know poses little threat to them.

A classic example of this is someone having a tough day at work. They may be very frustrated by it – they end up going home and shouting at their family for doing the slightest thing. This is the defence mechanism in action.

They don’t let their anger out on their colleagues, as they know this would cause negative consequences. They see their family as not posing a threat.

While it may seem cathartic for the individual at the time, they usually realise that how they acted was out of order, and an apology will often ensue. If possible, those around them should make them realise how unacceptable their behaviour was in order to stop them from doing the same again. If it isn’t nipped in the bud, the same process will cycle.


The defence mechanism of denial is universally-known, and is something so many of us do. This defence mechanism usually involves a person being unable to face reality, or failing to accept something that has already been proven as true.

The person may refuse to recognise something that has already taken place, or is going on in the present day – regardless of irrefutable evidence. The saying “you’re in denial” is directed at someone using this mechanism. 

An example would be a person suffering from alcoholism – or any other substance-related disorder. They may deny they have a problem, even though their behaviour is harming both themselves and those around them.

Someone using this defence will normally deny the truth as it would be too difficult for them to process. Or they may accept something happened, but playing down the significance of the event.

Using alcoholism as an example, a person may admit they consume a lot of alcohol, but refuse to accept it is problematic. Losing someone you love is another common example where denial is often seen. Sometimes as part of denial, a person will blame someone else.


Projection is a defence mechanism that will normally see a person attributing their own insecurities or feelings they find unacceptable about themselves on to another person.

Projection is normally an unconscious mechanism, and will commonly lead to a distortion of truth. Sigmund Freud suggested that projection was a way of avoiding uncomfortable repressed feelings about themselves.

Projection commonly leads to conflict. An example of projection is a married individual that has been tempted to cheat on his/her partner. But instead of accepting this, the person may start thinking that their partner is going to cheat on them, and that they are the problem.

They may even go as far to openly accuse their partner of cheating on them. Projection is a well-known symptom of conditions like Narcissistic Personality Disorder and Borderline Personality Disorder among other conditions.


While many defence mechanisms are negative in nature, sublimation is an example of a mostly-positive mechanism. Sublimation refers to a person that converts harmful thoughts into acts that are acceptable.

A person will commonly have an impulse to act in a way that would be unacceptable – perhaps socially, culturally or even in a way that is criminal in nature. But instead of acting in this way, the person will change these impulses into a behaviour that can be accepted.

A good example of sublimation is a person who has anger management problems, and has an impulse to take out his anger on other people – either by shouting at them, throwing objects at people or physically attacking them.

But instead of acting on these impulses, they choose to channel the feelings in a positive way, through using a punching bag and gloves to take out their anger. This way, they have an outlet for their harmful thoughts, but are acting in a way that doesn’t cause problems to themselves or anyone.


Intellectualisation is a defence mechanism that sees a person adopting a cold and unemotional stance when thinking about events. The idea is that when someone uses this mechanism, they will try and distance themselves from any situation that would normally cause emotional distress.

A person utilising this mechanism will avoid all emotions when acting in life. If something bad does happen to them, they will only focus on the intellectual part – which means they will try and educate themselves about the situation facing them. This is usually seen as a positive defence mechanism.

An example of this would be someone who has broken their collarbone following a car crash – they are aware that they have a long lay-off ahead of them, and that their life is going to be very different for a number of months.

But instead of letting themselves get emotional about this, the person will try and learn as much as they can about the collarbone, the typical rehabilitation program, and ways of improving the chances of a swift recovery. By distancing themselves emotionally, they will be able to limit feelings of despair about their injury.


Rationalisation is a mechanism that sees a person explain distressing events, feelings or behaviours in a logical manner – or in a “rational” way. But when doing so, the person will avoid the true nature of their feelings or associated behaviour.

So a person saves themselves from the shame, disappointment or embarrassment of an event or action, without damaging their self-esteem, and avoiding anxiety in the process. Essentially, it may be seen as “making excuses” for oneself.

An example of this would be a person attending an exam, and subsequently scoring low. Instead of admitting that they failed to prepare adequately, the person may suggest the exam was overly harsh or not marked correctly.

This results in a person not criticising themselves, and instead argue that external factors are to blame, rather than internal factors. It can be very difficult in dealing with people who use this defence mechanism. They would also typically be seen as very stubborn.


Many people use compartmentalisation in their everyday life. As the name would suggest, this defence mechanism involves a person separating their life into different compartments, to ensure they don’t negatively affect other areas.

It involves avoiding the anxiety that comes from contradictory values, emotions or feelings. This defence mechanism allows a person to keep all different areas of their life under control.

An example of this would be a line manager shouting at one of their subordinates for doing something wrong. Yet when this line manager goes home to their family, they wouldn’t even entertain the possibility of shouting at them the way they did with their subordinate at work.

The person will therefore be compartmentalising their life; while these two states (angry line manager and doting family man/woman) wouldn’t normally mix, a person may do this in order to protect themselves from possible harm. A person who went into work and treated their employees like they would their family may find that they rapidly lose respect.

This is generally a defence mechanism that is about control – many people find it to be something that gives them the best of various worlds. While this defence mechanism might be positive in some ways, it can also be negative.


Introjection is a defence mechanism that a person may use in a variety of instances. It is generally used by a person that decides to act in a certain way, or behave differently – in an effort to “fit in” more or become more likeable. It is rather sad defence mechanism that has many consequences.

It is most commonly seen in children who don’t feel close to their parents. The child may try and replicate the behaviour of their parents, or start talking about similar things to them, in an effort to try and improve a relationship.

An example would be a new pupil at school, who tries to embed themselves in a new friendship group. When playing with them for the first few days, they notice that the group commonly say the word ‘awesome’ when describing something in a positive way. The new pupil starts using that word around them, and in everyday life, in an effort to become more like their peers, and improve their relationship. This may come at the cost of not being able to act exactly how one wishes.

This mechanism can be used to help protect an individual from feelings of neglect, loneliness or some forms of anxiety. This can lead to a person losing a sense of their own self – which is a common cause of mental health problems developing.

Reaction Formation

When a person uses this defence mechanism, they are able to understand their feelings and thoughts towards something, but they actively behave in the opposite manner. It can also be seen as an extreme form of denial.

A person may feel anxiety due to their feelings and thoughts towards something, so as a way of coping with this, they choose to consciously act in a completely contrasting manner to overcompensate for these harmful areas.

An example would be a man who is homosexual, but does not tell anyone. When starting a new job in a rather ‘macho’ environment, he doesn’t think he would be accepted because of his sexuality. So instead of acting as he normally would, the person goes out of his way to joke about homosexuality, and even criticise homosexuals as a way of trying to ensure his co-workers do not suspect his real sexuality.

The person may even make overt efforts to sleep with women as a way of trying to convince himself of his actual sexuality. This can result in a person losing a sense of their own self – which as discussed earlier, commonly causes mental health problems.


Self-Harm is a defence mechanism that some people use as a way of coping with overwhelming emotions, traumatic memories or difficult feelings. Regrettably, it is a very common defence mechanism.

But self-harm isn’t always physical in nature. Breaking down the use of self-harm as a defence mechanism – it can normally be categorised in one of three areas: conversion, somatisation or physical self-harm:

  • Conversion involves a person unconsciously turning stress into physical symptoms.
  • Somatisation involves someone transforming uncomfortable feelings towards others into their own feelings.
  • Physical self-harm is the conscious effort of cutting, hitting or burning oneself.

While self-harm is most associated with teenagers, if a person finds the action helps them cope, the behaviour may continue into adulthood. Someone who engages in self-harm may not have a healthier coping mechanism to use.

The explanation behind this defence mechanism is that some people will find self-harm can provide an emotional release from intense psychological pain. But these methods merely paper over the cracks, and does not help with treating the causes behind the intense emotional pain.

For instance, a person may be going through a difficult episode of depression. Multiple areas of their life may be being impacted, and they are struggling to cope with day-to-day life. They may even have some suicidal ideation. They find that by self-harming, they are able to release psychological distress, and that physical pain may be more preferable.


Isolation is a defence mechanism that involves a person ensuring there is a gap in thought processes when thinking about a difficult or traumatic memory, feeling or thought.

The idea is that when any such feeling or thought comes into a person’s mind, they immediately pause, take a few seconds as a break, and then actively thinking about another subject.

This process can continue for a long time. While it doesn’t deal with long-term implications, it can be effective in the short-term. When a person does this, it signals to the mind that these thoughts or feelings are damaging, and it may lead to the thoughts becoming less recurrent.

An example would be a person who has been called to a meeting with their boss. The manager speaks of their disappointment of a person’s recent work. The person uses this defence mechanism, and leaves satisfied with their performance, regardless of the feedback.

They keep the feedback isolated from their efforts. Whenever they start to think of the feedback, the person stops, then after a few seconds moves on to thinking about a different subject. It can help some people to focus on the positives, rather than the negatives.

Aim inhibition

Aim inhibition is a defence mechanism involving a person not being able to complete certain desires or goals, so then, they subsequently lower their goals to something more achievable.

Aim inhibition isn’t generally seen as a negative defence mechanism, and is positive in many cases. But if this mechanism causes a person to feel jealous of others who did achieve their original goal, it can lead to feelings of distress.

An example would be a person aiming to become a dentist. They do not score the required marks on a test to become a dentist. Instead, they become a dentist’s assistant. This way, they are able to be close to their original goal, while still making a general contribution. The person has at least achieved this goal.

They may feel bitter or jealous however, about those that did qualify as dentists. If this is the case, resentment can follow, and they will typically become sad about their decisions.


Altruism is defined as a selfless concern for the wellbeing of others. There is great debate as to whether or not this is a positive or negative defence mechanism to have.

A person who is an altruist will typically occupy their time wherever possible by helping others. They do this to improve their own mental wellbeing. They may believe that by avoiding their own problems and issues, a person can improve their mood by improving the mood of others.

But this does run the risk of a person becoming used by others. At some point, they may start feeling as if they have been taken advantage of. The saying “if you give them an inch, they’ll take a mile” becomes incredibly true.

Other defence mechanisms

As alluded to earlier, there have been a range of other defence mechanisms proposed by various people throughout history. Briefly, other mechanisms often mentioned include:

  • Acting-out: This is an individual who directly expresses or acts out an unconscious wish/feeling, or an impulse. They are not consciously aware of what has driven this behaviour
  • Avoidance: This is where a person physically removes themselves from certain areas, events or a stimulus. This is because these happenings may lead to someone being reminded of difficult or traumatic thoughts or memories. This is commonly seen in Post-Traumatic Stress Disorder.
  • Humour: This is a very well-known emotion, and some people use humour to distance themselves from difficult psychological feelings about something. Someone may self-depreciate, which may entertain others. It can help a person feel less anxious about the feelings they face.
  • Passive-Aggression: A person who uses this mechanism may try and mask their aggression over a stress by acting in a passive manner. A person may agree to do something, but they resist doing whatever is involved in subtle ways. The person who was asking the other to help may feel the person is making it difficult. The person using this mechanism will use it as an outlet for their aggressive feelings over a certain situation.
  • Undoing: As the name suggests, it involves undoing something from the past, or trying to do something positive to cancel out the negative. A person who has upset someone may go out of their way to do something nice for the person, lessening their guilt in the process.
  • Fantasy: This is where a person avoids the reality of a situation and retreats into their mind and think about an alternate reality. Fantasy allows someone to be in the safe place of their mind, and avoid thinking of the harmful reality of a situation.


Defence mechanisms are a crucial part of life – and it is important to remember that they are natural occurrences. In many cases, they don’t cause harm. But sometimes, these mechanisms can actually lead to a person encountering psychological distress, and eventually a mental health condition may develop.

It is important to monitor one’s mental wellbeing. If a person does feel very bad mentally, then a form of therapy should be able to help them identify problematic areas – some of which may include defence mechanisms. With the right treatment, harmful mechanisms can be identified and treated.

See Also


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