Id, ego, and superego are theoretical constructs given by Sigmund Freud. These are three parts of our mind. They interact with each other and guide our behavior. Since their interaction with one another guides our overall behaviour, it determines who we are – our personality. Therefore, it is also correct to say that these are three parts of our personality.

These three parts (id, ego, and superego) are equally important for a healthy personality because each part has its vital function. For instance, id constitutes the part of the personality that consists of needs and desires. Ego ensures that these needs and desires are fulfilled in a rational and realistic manner. Superego ensures that moralistic considerations may not be bypassed for the fulfillment of the needs and desires. These three parts of the personality are explained in detail, as follows.

Id is the primary part of the personality which consists of instincts and innate biological drives (e.g., hunger, thirst, sleep, sex, to be relieved from pain). According to Freud, an individual is born with certain instincts and biological drives which influence his behaviour throughout his life. For instance, sex and aggression are two instincts. An individual shows a desire (libido) for sex because it is his inborn instinct. Similarly, the expression of aggressive behavior is because of the inborn instinct for aggression.

According to Freud, id work on the pleasure-seeking principle. This is because an instinct is basically a drive that needs to be met. When an instinct is not fulfilled, it creates a state of tension or pain. In order to reduce this state of tension, the instinct compels an individual to engage in a pleasure-seeking behavior. For instance, if an individual feels hungry, he will experience a state of tension which drives him to eat something to reduce the state of tension.

According to Freud, id may not care about logical or rational considerations but only wants to reduce the state of tension caused by instinctual drives. This means that id is only concerned about the reduction of tension without carrying whether the route to goal achievement is right or wrong. This does not necessarily mean that all human behaviours (caused by id) would involve socially unacceptable ways of goal achievement because there are two other mechanisms (ego and superego) that regulate the expression of id. However, as far as the id alone is concerned, it only cares about tension reduction.    

Moreover, id constitutes the unconscious part of personality. This means that it responds immediately and unconsciously (or involuntarily) to the needs, urges and desires of the body. For instance, id would automatically respond to the state of tension caused by an instinctual drive to reduce it by avoiding pain or seeking pleasure. This means the reflex actions are also id controlled.

Reflex actions that are inborn automatic (involuntary) actions. For instance, when we touch some hot object (e.g., iron used for pressing clothes) by mistake, we automatically (or unconsciously) withdraw our hand. It is a sudden involuntary reflex action to protect our hand from being burnt. Similarly, if we see something coming toward our eyes (e.g., a ball thrown at us), our eye suddenly blinks (shuts for a moment) to protect the eyeball from being hurt. Likewise, our eyeball has a small window (or hole) called a pupil that shrinks and expands to control the amount of light being entered through it. It automatically shrinks when we see a strong bright light so that a small amount of light may be allowed to enter through it.

The ego is the part of the personality that provides logical and rational criteria for behavior. It is the decision-making component of personality which makes decisions based on the perception of the external world. It decides how to perform an action in accordance with external circumstances.

Id always wants to fulfil its desires or needs to seek pleasure. Since id is unrealistic and wants to fulfill its desire without caring about the external real world. However, ego determines how the desire (of id) should be fulfilled in a proper way and in accordance with the external real world. For instance, a student feels hungry while listening to a lecture in the classroom, id urges to eat something but ego signals that it is not appropriate to start eating in the classroom while the teacher is delivering a lecture, therefore, it is better to wait until the class ends and then eat something. This is why even if the student has something (e.g., a burger) in his bag, he would wait until the class ends and then go outside the class to eat at some place.

Id works on the reality principle. It regulates the desire expression of id to make the resultant behavior suited to the external real circumstances. Unlike id which is irrational, ego is a rational part of the personality. Ego weighs the pros and cons of different ways to fulfil id’s desire and decides the best rational and logical way to fulfill id’s desire. If a desire cannot be met in a realistic manner, ego may engage in secondary process. The secondary process is a mechanism of ego to relieve the state of tension when as instinctual desire cannot be fulfilled due to some reason or when the desire is unacceptable. It does so by forming a mental image for what it desires but cannot get it. For instance, a man is hungry but cannot get food at some time, he may form an image of pizza in his mind to get temporary relief in hunger. Another example: if a person loves someone romantically but social considerations do not allow him or her to enjoy the company of his or her beloved, the lover may make mental images of his or her beloved and fantasizing it to get temporary pleasure.

Id consists of innate instincts and biological drives. It means that id is present in an individual since his birth. However, ego is not present right at the time of birth. As the individual matures, he develops an ego which strengthens over the course of his life. For this reason, a little kid may perform many actions without caring about the external real world. For instance, a baby, feeling hungry, would want milk without caring much about external circumstances. However, as the kid keeps growing, he starts thinking about what should be done when, where and how, so that his desires can be fulfilled in a realistic and appropriate way. This means that ego, a logical and rational sense, is not present at birth but is developed slowly and gradually as a result of interactions and experiences with others in society.

Superego is the part of the personality that consists of morals and values of society which we learn from our parents and others. According to Freud, an individual develops superego at the age of 3 to 5 years.

It controls id’s desires, particularly those which are socially and morally unacceptable such as sex and aggression. For instance, sex is an instinctual need of a person, but society forbids it if it is fulfilled in a socially and morally unacceptable way. Due to the superego, the individual refrains from the socially unacceptable and immoral expression of sexual desire. Therefore, the individual may express it and fulfill it in a socially acceptable manner.

It is important to understand the difference between ego and superego. First, the superego, as its name indicate is the sophisticated form of ego. Second, the superego is more concerned about moralistic goals whereas ego is more concerned about realistic goals. Third, superego makes decision-based on moral and values whereas ego makes a decision based on rational and logical judgement. This means that if id’s desire involves only rational considerations, it is appropriated by ego. On the other hand, if id’s desire involves moralistic considerations (such as that it challenges the morals and values), it is appropriated by the superego.

Superego wants perfectionism. It strives to make a person morally perfect. This does so by its two systems: 1) conscience and 2) ideal self.

The conscience punishes for doing things against morals and values. It does so by triggering feelings of guilt in an individual after he does something against morals and values.

The ideal self is the individual’s perception of himself such as that how he should be as a person. For instance, how should he behave with or treat others in society. This perception of one’s self (ideal self) is based on higher standards of morals and values which are respected by the individual. The ideal self works as a yardstick for an individual to gauge his own actions as good or bad. The ideal self also rewards an individual if he does something in accordance with high standards of morals and values. It does so by triggering feelings of happiness and proudness in the individual after doing something good.

All the three parts of the personality (id, ego, and superego) are equally important. Therefore, if all these three components work properly, it leads to a healthy personality. It may be thought that if only id (instincts and biological drives) and superego (morals and value-based judgement) work properly, it can assure a healthy personality. However, this is not true. This is because, apart from the rational judgement function of ego, the function of the ego is also to mediate between id and superego – to bring a balance between id and superego.

For instance, if id expresses some desire and the superego shows extreme resistance to this desire id. In such a case, sometimes this may lead to an extreme psychological clash between id and superego leading to frustration. This is where the ego comes to mediate: ego brings in rationality to calm down id to some extent as well as gives a little relief to the id by some alternative means such as secondary process.

Hence, if the ego is not working properly, either id or superego may take control of the personality system and the person will suffer personality abnormalities.