editorial: personality - the biological perspectives

ROMANIAN JOURNAL OF
EXPERIMENTAL APPLIED PSYCHOLOGY
VOL. 5, ISSUE 3
–
www.rjeap.ro
EDITORIAL: PERSONALITY - THE BIOLOGICAL
PERSPECTIVES
MIHAI ANIȚEI, PHD.
University of Bucharest, Faculty of Psychology and Educational Sciences,
Department of Doctoral School
Since ancient times, the Greek philosophers attempted to explain human
personality. They believed that the human behavior types are caused by the fluids
in the human body. Philosophers believed that excess blood determines sanguine
temperament, excess black bile causes melancholic temperament, excess yellow
bile determines hot temper while excess phlegm leads to a phlegmatic
temperament. Of course this is a purely theoretical approach, this perspective never
having been empirically tested (Canli, 2006). Temperament refers to a person's
characteristic emotional nature, including sensitivity to emotional stimulating,
specific reaction speed, prevailing mood condition, and all peculiarities of
fluctuation and intensity of dispositional state, all of which are considered to be
dependent on the person's physical structure and hereditary determined "(Allport,
1937, as cited in Ryckman, 2008).
Ivan Pavlov, one of the greatest psychologists, a physiologist at base,
investigated stimulus-response type simple classical conditioning. Pavlov identified
three properties (strength, mobility, balance) that determine the structure of the
central nervous system (Ryckman, 2008). Strength reflects the energetic capacity
of the neuron, being genetically determined, mobility refers to the dynamics of
fundamental mental processes, the need to shift from a mental process to another,
and balance is the ratio of excitation and inhibition.
After studying canine behavior, Pavlov developed four temperament types
which are specific to humans as well: 1) weak type characterized by anxiety,
inhibition, low tolerance to stress; 2) highly-unbalanced type characterized by
excitability, hyperactivity and irritability; 3) strong-balanced-inert type
characterized by steadiness, calm, high tolerance to stress and frustration; 4)
strong-balanced-mobile type characterized by liveliness, motivation, energy
oriented outwards (Ryckman, 2008).
Another psychophysiological mechanisms perspective is that of Enrst
Kretschmer who, by studying psychiatric patients, determined that these disorders
arerelated to physical constitution. Thus, he concluded that there are three main
types: 1) picnic - bulky abdomen, overweight, stretched skin, horizontal
constitution, 2) asthenic- flat rib cage, small, round head, long, sharp nose,
feminine features on men and masculine features on women; 3) athletic- welldeveloped, muscular, broad shoulders, balanced physical constitution (Ashton,
2013). William Sheldon continued the study of these types calling them
somatosensory types using different names for each type. Picnic type is called
endomorph, the term ectomorph is used for the asthenic type and mesomorphs
describes the athletic type (Ashton, 2013).
Robert Cloninger developed a model that tests the neurotransmitters influence
on personality traits. More broadly, the neurotransmitters are biochemical
substances that are involved in communication between nerve cells called neurons
(Ashton, 2013). Considering how neurons communicate, we can say that neurons
are the basis of thoughts, emotions and human behavior and the substances in the
body can influence human behavior (Ashton, 2013). The major neurotransmitters
are found in the central nervous system and in the bone marrow and they are
serotonin, dopamine and norephinephrine. (Ashton, 2013). Dopamine helps
neurons transmit impulses about the existence of things that people consider to be
good or are seen as rewards. Individuals characterized by high levels of dopamine
are those who seek excitability, excitement, everything new. This dimension of
personality has features like extravagance, opulence, lack of organization,
excitability, impulsiveness. In contrast, there are people who do not seek
excitement or fun (Larsen & Buss, 2008). The second neurotransmitter is serotonin,
a neurotransmitter that inhibits signal transmission on punishment, with the
purpose to stop the neurons from sending impulses when there are stimuli that
represent punishment. Serotonin is related to states like anxiety, tension or pain
(Larsen & Buss, 2008). The third neurotransmitter is norepinephrine.
Norepinephrine is known as having a role in inhibiting responses to conditioned
stimuli, the stimuli that have been associated with rewards. Norepinephrine has a
strong relationship with behaviors that generate pleasure (Larsen & Buss, 2008).
Another important model is that of Jeffrey Gray, in which he argued that the
brain has different regions, and certain functions involving interactions between
multiple brain regions and personality traits influence human behavior (Canli ,
2006). The two systems described by Jeffrey Gray are The Behavioral Activation
System and The Behavioral Inhibition System. The Behavioral Activation System
is composed of brain regions that are responsible for receiving signals from the
nervous system side which indicates a situation in which reward may be
experienced (Canli, 2006). The Behavioral Activation System is related to
Cloninger's model in terms of dopamine. Gray argued that the behavioral activation
system is different for each person, being more or less sensitive to stimuli showing
reward. The behavioral inhibition system is composed of brain regions that are
responsible with the reception of signals from the nervous system, which indicates
the existence of situations in which punishment or suffering are experienced (Canli,
2006). This system serves to stop behaviors that denote avoidance of punishment
and suffering. Another biological model of personality is that of Hans Eysenck. He
developed three major personality factors (Extraversion, Neuroticism and
6
Psychoticism) and claimed that human behavior is based on the variation of the
central nervous system excitability (Burger, 2007; Ryckman, 2008).
Another view of the biological model is the alternative model with five
factors of personality of Marvin Zuckerman in which he tried to observe the
biological perspective of a number of personality factors using factor analysis.
Thus, he developed factors such as: activity, sociability, impulsivity thrill-seeking,
aggressiveness and neuroticism-anxiety. According to Zuckerman each personality
trait is determined by a unique combination of neurotransmitters between brain
structures (Larsen & Buss, 2008).
REFERENCES
Ashton, M.C., (2013). Individual Differences and Personality, second edition.London:
Elsevier.
Burger, J.M., (2007). Personality, 7th edition. Belmont: Thomson Wadsworth.
Canli, T., (2006). Biology of Personality and Individual Differences. New York:
Guilford Press
Larsen, R.J., & Buss,D.M., (2008). Personality Psychology. Domains of Knowledge
about human nature ,3th edition. New York: McGraw Hill.
Ryckman, R.M., (2008). Theories of personality. Belmont: Thomson Wadsworth.
7