User:Psyc452-BFrancisco/Evolutionary psychology of Personality

Evolutionary Psychology of Personality
Evolutionary psychologists agree that personality differences evolved from psychological mechanisms that help guide human behavior in response to the various adaptive problems of our ancestors. These numerous mechanisms are species-typical and domain-specific to solve specific adaptive problems. Humans evolved as a group of living species negotiating and competing for various resources and hierarchical status to further their fitness. Those that responded with the necessary mechanism that would succeed in attaining those resources or status would survive. Therefore, for any trait to have importance it must have variability from its competitors. For example, extroverts are more open to the adventures of exploring new territory (allocating new resources) and are more social and friendly (which increases their reproductive success). However, they are much more likely than introverts to be exposed to dangerous pathogens from exploring unknown grounds or mingling with other people.

There are multiple evolutionary theoretical approaches which attempt to explain the roots for why differences in human psychological mechanisms encourage variations in personality traits. Some of the most common speculations include personality traits being due to life-history theory, costly signaling theory, fitness optima, frequency-dependent, and flexibility contingent shifts depending on environmental conditions.

Life-history theory describes personality and individual differences as a response to the different trade-offs different individuals make in respect to capturing and allocating energy. Everything an individual does in life, whether it be growing or maintaining it’s own body, trying to reproduce, or rearing a child, cost valuable energy. Since energy is not limitless trade-off exists between the adaptive issues we encounter. In this sense, the energy spent searching new territory and food, cannot be spent on raising a child, it’s one or the other. It is hypothesized that this trade-off encompasses personality as well. Extroverts have an increased mating success and develop more social alliances, however, this trait comes with the trade-off of being exposed to high levels of risk. The decisions humans make behaviorally and cognitively create a trade-off that established individual differences and various personalities. Costly signaling theory is based on the face that individuals compete for resources and mating partners by sending signals about themselves. Only individuals in the best condition, physically, economically, with high energy can spare the energy it costs to send out these signals. Character traits such as altruism, generosity, courage, and strength can only be expressed by those that can afford to use energy on it. So it is hypothesized that these expressions sends signals to other individuals informing them of their fitness. Fitness optima bases individual differences in personality due to natural selection favoring different levels of personality traits in different environments. (Buss, 2009) It has been shown that geographical differences exist in accordance with the Big Five personality triats. For example, people in California, New York, and Florida are more open to experience. New York also houses a majority of neurotic people.

Frequency-dependent selection theory states that two or more strategies exist within a population at certain frequencies relative to one another, such that if one strategy is more prominent and common in the population it decreases your fitness. In other words, natural selection chooses those strategies that are less popular, favoring the alternative strategy. An example of this is biological sex, as the male to female ratio increases, males fitness ultimately decreases. Research shows that personality differences are most prominent in social species, therefore it might be the social environment that provide various adaptive situations which require different personality strategies to succeed. The contingent shifts theory argues that personality traits are contingent upon or present in response to the environment of which it is exposed. . In other words, it is hypothesized that our psychological mechanisms are activated and operate in response to changes in environmental conditions. Contingent shifts can occur in response to conditions of life-history theory (as when a man shifts to a more conservative, less risky behavior after fathering a child), costly signaling theory (as when environmental conditions make sending signals less costly), during situation-specific conditions (becoming more aggressive and risky during times of famine when food is scarce), when an individuals social status changes, and even in response to heritable phenotypic qualities. The main point here is that contingent shifts can occur in response to both the internal and external environment.

Evolutionary Psychology and Personality Psychology
Evolutionary psychology examines the variation between species and seeks to identify specific evolved psychological mechanisms that explain human nature. Personality psychology examines the proximate explanations for individual differences between people. Viewing personality and individual differences through evolutionary theory has potential to enrich personality theory and to uncover the ultimate causes of personality characteristics. David Buss proposes that personality characteristics may not reflect noise or by products of other adaptations, but might have an adaptive function. It is hypothesized that these adaptations have led to five major personality traits which have been beneficial to human reproductive fitness.

An evolutionary theoretical framework can supplement and enhance current personality theory about the adaptive functions for genetic differences that influence personality, potential proximate mechanisms of how personality works and is constructed, and how responsive an individual is to certain aspects of the environment.

Evolutionary Theory Regarding The Big Five Personality Traits
The big five personality traits reference particular human qualities that are speculated to have influenced evolutionary behavior for our ancestors. For example, there are sex differences in personality, attributed to differences in male and female reproductive strategies performed in the ancestral environment. Traits for dominance and aggression are seen as more beneficial to the reproductive fitness of men, thereby the selection of these traits in women are lower and more relaxed.

Individual variations of these personality traits are theorized to balance along an ever changing optimum dependant on place and time. The trait of openness encompasses an individual’s ability to form creative connections between concepts and is associated with artistic ability. In terms of fitness benefits, research has shown that higher levels of openness and creativity are associated with a higher instances of being perceived attractive by the opposite sex, resulting in a greater ability to attract a mate. In contrast, high levels of this trait have been associated with some severe psychological disorders, which indicates that extremely creative thinking can be damaging the overall mental health of an individual. In these cases, the ability to attract a mate and the likelihood for reproductive success become significantly lower. Conscientiousness is the ability to think before acting. It is generally seen as beneficial to have higher amounts of this trait because it environmental awareness and caution promotes the survival an individual. Yet those who are much higher than the optimum level are at a severe disadvantage when immediate opportunities arise, and often miss the benefits of these spontaneous opportunities, thereby indicating that too much conscientiousness can be damaging to an individual's fitness. Extraversion is positively correlated with various mating advantages, including number and quality of sexual partners, both of which are associated with an increase in fitness. Not only is the trait beneficial for sexual reproduction, but it is also associated with higher sociability and social support, which further indicates the trait's evolutionary benefits. Studies have shown that variation in extraversion also predicts patterns of physical strength and attractiveness, and individual differences in this characteristic is most likely a result of prior reproductive strategies. In contrast, there are limits to the benefits of extraversion due to risks involved in such behavior. An individual high in extraversion is more likely in their lifetime to be hospitalized, involved in criminal activities, and susceptible to divorce. An individual exhibiting too much trust and empathy towards others is prone to being taken advantage of, which can endanger their well-being, especially in potentially life threatening situations. The negative effects of high neuroticism include an increase in depression and/or anxiety as well as impaired health in general (due to the overworking of the body’s stress mechanisms). In regards to social livelihood, high amounts of neuroticism are often predictive of loner behavior and relationship failures. Although it is difficult to determine a functional reason for the normal distribution of neuroticism within the population due to the plethora of negative behaviors associated with the trait, it is hypothesized that in the ancestral environment, a level of neuroticism was critical for threat detection and avoidance of danger. Neuroticism is also linked to competitiveness and strive, therefore a certain amount within an individual holds the functional value of aiding in achievement within competitive situations.

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