Sigmund Freud was born in 1856 in Austria to a jewish family. He was trained as a physician at the University of Vienna. His speciality was in neurology. In addition, he has worked as a psychiatrist and has seen many psychiatric patients during his medical practice and during the formulation of his theory of psychoanalysis.
Later in his life Freud abandoned neurology and started to look at psychiatric patients. He has looked at personality from a purely biological point of view. His assertion is that personality of humans can be traced back to biological instincts located in every person.
There is a correlation between personality and biology according to Freud. Behaviour, thinking and feeling all can be traced to biological reasons according to his theory.
He assumed that people are similar to animals because their behaviour is governed by their biological instincts. In addition he assumed that every behaviour has meaning and has purpose.
He also asserted that personality is hedonistic. Namely it functions based on the pleasure principle. People behave in such a way as to satisfy their biological needs and by avoiding events that can trigger pain.
Thus the aim of all human behaviour is to satisfy his physiological needs. He said that no matter how our makings are good or our behaviour is noble, they are all guided by a process of satisfying our instinctual needs. These instincts are born with us and are strong forces which direct our behaviour and motives.
Freud used the term Libido as a description of the instinctual drives in each person. It describes also the energy associated with the biological drives. Libido is the energy which guides the motives and direct them in the direction of behaviour manifestation.
In the beginning of his theory Freud considered Libido to be sexual drive only. After the development of his theory he added to this term all instincts in the individual.
Eros according to Freud is a term which denotes all self maintaining processes. Individuals spend libidinal energy in order to maintain life in addition to supporting behaviour that satisfy our biological needs such as hunger and thirst and sex.
In addition to the self preserving forces that the person has and which he calls Eros, Freud asserted that individuals have in addition destructive forces which he called thanatus.
These forces work in opposition to the self preserving forces the erros. An example of such an instinct is the aggression that an individual can have.
The levels of personality according to Freud include three levels. These are the conscious and the unconscious and the preconscious mind. The preconscious is available to consciousness while the unconscious is not available to us and is considered repressed memory according to Freud. It directs behaviour without our knowledge.
The personality of humans is composed of three structures according to Freud. These are the id and the ego and the superego. The id represents the instincts within us such as hunger and sex.
Freud claimed that new born children's life work based on the pleasure principle in which the child seeks to satisfy his biological needs instantly. The ego is the second structure of personality. It works based on the reality principle defering the instinctual needs of the indvidual until the time is socially appropriate.
The third structure of personality is the superego or the conscience of the individual. The superego is formed during childhood by internalizing the normes and social rules of the society and by internalizing the values of our parents.
Personality development according to Freud is designed in childhood time and every child undergoes several stages of development. Each of which is crucial for the healthy development of the child. Fixation is a psychological disorder which can happen at any stage of the personality develpment during childhood.