The organic and functional structure of the brain constitutes the physical support of the mental processes that provide the psychic capacities necessary for the perception of oneself and for the establishment of relationships with their environment, interpreting the stimuli coming from it and choosing the response to the themselves. The importance of this structure in the formation of the traits can be verified in those cases in which the anomalies of this cause personality disorders, as the paranoid, antisocialobsessive compulsive or limit.
Brain structures and personality traits
Traits related to anxiety, conditioned fears or avoidance of harm have been found to be associated with a increased activity of the amygdala and the serotonergic system, while impulsivity, search for new sensations or psychoticism are mainly related to the striated nucleus and the dopamine system.
Relationship between brain and personality
Considering that the personality reflects the way of thinking, feeling and acting of the person, the Brain structures that make these functions possible are found in cognitive systems, emotional and motor; and the training, organization and functionality of the same comes
The main function of these three brain systems in the construction of personality traits is to provide the following capabilities:
- Cognitive system: ability to interpret and assess events in the environment (reasoning) and to perceive one's own mental states (introspection) resulting from that work.
- Emotional system: ability to recognize and express one's own emotions (emotionality), be receptive to the emotions of others and share them (empathy).
- Drive system: ability to respond appropriately to the presented stimulus (impulsiveness) taking into account the circumstances in which it takes place.
Brain chemistry and the way of being
We use these capabilities to process the information received from the environment in order to understand the world around us and choose how to relate to it. A fundamental factor in the processing and transmission of information is the type and concentration of neurotransmitters and synaptic receptors that act as mediators in the cognitive, emotional and motor processes involved in the formation of a certain trait.
For example, low serotonin levels are associated with poor emotional regulation (dysthymia, aggressiveness, bad mood, negative thoughts, etc.), and low levels of dopamine are associated with problems of social anxiety, apathy, anhedonia, etc., while high levels are associated with hyperarousal, hypersexuality and hypersocialization.
Also hormones intervene (especially the thyroid and adrenal), thus, physical, emotional and mental apathy can be due to low levels of catecholamines (adrenaline and norepinephrine) or low levels of hormones thyroid, and the most outgoing people have high levels of catecholamines while the more introverted, quiet and calm ones have lower levels. Likewise, there is a close relationship between the behavior characteristic of the aggressive person and higher levels of testosterone.
These capabilities are available to anyone, but they do not contribute in equal measure to the formation of their personality, since the potentiality and degree of development of each capacity vary according to the person (it depends on the genome). Actually, what determines capacity is a tendency or predisposition towards a concrete way of interpreting the stimuli, assessing them and choosing a response, aspects that are fundamental in the formation of the trait.
Thus, a great cognitive capacity will originate a predisposition towards traits of self-confidence, self-sufficiency and self-control, however, a reduced capacity will make it towards traits of prudence, withdrawal, insecurity or distrust. Likewise, a high emotional sensitivity will direct her towards traits of sociability, kindness, solidarity and affectivity, while a loss will make it towards aggressiveness, intolerance or authoritarianism. The same will happen in cases of high or low impulsivity, which will set the tendency towards an active response (enterprising, restless, impatient) or passive (submissive, calm, calm).
Temperament: the inherited part of the personality
Is tendency or predisposition of genetic origin towards one trait or another constitutes the basis of temperament. According to psychologists and geneticists Arnold Buss and Robert Plomin, temperament would be "inherited personality traits, present from birth and have a greater genetic basis." Through factor analysis, both authors identified three temperament dimensions on which it is possible to speak of genetic influence:
- Emotional versus impassive. The emotional person is easily excited and responds with greater intensity than the impassive.
- Active versus lethargic. The active person is usually busy and in a hurry compared to the slower paced lethargic.
- Sociable versus separate. The Sociable person looks for others and has a preference for being with other people, however the separated person tends to prefer to be alone.
Furthermore, Buss suggested that temperaments are considered as a subset of personality traits delineated by manifestation in the first year of life, later perseverance and genetic transmission. Emotionality, activity, and sociability are three personality traits that meet these measures. What is inherited tend to fit into a particular range on each of the temperament dimensions.
As noted above, biological structure defines behavioral trends within a spectrum of traits, but it does not specify or determine the behavior to follow in the face of a specific presents. It does not tell us, for example, why we interpret a stimulus to be beneficial or harmful and how we should act under the circumstances. Therefore, the question that arises is: how is an action chosen in response to the perceived stimulus and how is it maintained over time until a trait is formed?
From predisposition to personality trait
This task depends fundamentally on the way the person uses and develops skills mentioned psychic to elaborate thoughts, affections and behaviors. This function is performed through the psychological structure, which contains the necessary instructions to perceive a stimulus from the environment, interpret it, give it a meaning and an assessment and choose the response to it (the model of stimulus-response). In this sense it could be said that the psychological structure does not modify the biological structure, but rather "manages" it to adapt it to the requirements of environmental stimuli.
The influence of the environment
These instructions are contained (according to the functional model of the mind) in the various mental programs: perception, attention, evaluation, interpretation, memory, emotion, motivation, intention, choice, etc., that are generated through learning obtained through the interaction of the person with their close environment, whether family, work or social (the figure of attachment is important). It is, therefore, the environment in which a person develops (in which the reigning culture has a great influence) the source of knowledge, beliefs, traditions, experiences, moral values, motivations, etc. that contribute to the formation of these programs.
In this sense, Buss and Plomin suggest that various innate or inherited dispositions that contribute to the structuring of the personality are influenced by the interaction with the environment and that this interaction is particularly important in early childhood, although there are limits to how much the environment can modify basic layout.
But each situation is accompanied by different environmental circumstances, so the behavioral response will necessarily be influenced by them (by For example, a reserved person may not manifest that trait in the same way always, at all times and in all places, it will be to a greater or lesser extent according to the circumstances). The way to find out if a given trait is invariant or independent of the environmental situation is investigate their behavior in various situations and, if the trait continues to manifest itself in the same way, it is understood that it is invariant and is part of the personality.
The role of emotions in the consolidation of behavior patterns
As for the transformation of a certain behavior into a personality trait, it will depend on the evaluation of its result. A conduct is considered appropriate and will remain constant and stable until become a trait whenever useful to achieve the expected objective and we are convinced that it is the correct one, and this depends largely on the reaction of the emotional system Given the observed result, so that if it makes us "feel good" (the reward system is activated by increasing the release of dopamine that generates a state of well-being) will cause the behavioral response to be repeated and, after successive satisfactory repetitions, it will become feature. But if it causes us displeasure and dissatisfaction (the tonsillar system is activated) it will decrease the probability that it will recur.
In this regard, the psychologist Jeffrey Alan Gray (1970) presented his factorial-biological theory on the structure and bases of inter-individual differences in personality and described two main biological mechanisms that determine the tendencies of behaviour. He called one of them "behavioral approach mechanism" and the other "behavioral inhibition mechanism"; These would be equivalent to the basic factors of the personality, which would have a physiological basis. This behavioral system favors the approach to stimuli and novel situations and is mainly activated before the possibility of obtaining a reinforcement, unlike the behavioral inhibition mechanism, which depends on the punishment.
Character: the learned part of the personality
The set of traits generated by the psychological structure through this procedure set character. Ernest Kretschmer, a German researcher on the constitution of character, affirms that this “results from the set of fundamental biological characteristics based on the anatomical-physiological substrates of the individual constitution and of the characteristics that develop under the influence of the environment and special individual experiences. This means that character is part of a process and is in our way of relating to the environment and to the internal phenomena of our mind, therefore, it is not something that remains fixed”. There then, the typical question would be answered: Can you change your personality? As we can see, a part can be molded.
