Biological Theories - READINGS Flashcards
Pro and con of Darwin’s theory:
- Darwin’s theories of natural and sexual selection provided the light and the way for understanding struggles for existence and struggles for mates
- At the same time, Darwin failed to identify several key evolutionary struggles revealed by successive scientific revolutions within evolutionary biology.
The theory of natural selection made four important contributions:
- First, it explained change over time in organic design, “descent with modification.”
- Second, it furnished the causal process by which different species originate
- Third, it explained the seemingly purposive quality of the component parts—their adaptive functions, or the particular ways in which these characteristics aid survival
- Fourth, natural selection unified all species past and present, including humans, into one grand tree of descent
- We knew for the first time in history our true place in nature.
Darwin identified three classes of survival struggles that form the core of important research in evolutionary psychology today:
“As more individuals are produced than can possibly survive, there must in every case be a struggle for existence, either…
- one individual with another of the same species
- or with individuals of different species
- or with the physical conditions of life
- These struggles have spawned discoveries in modern evolutionary psychology
Struggles with the natural conditions of life
Evolution of Aesthetics
- Evolutionary psychologists have discovered plausible candidate adaptations produced by some of these hostile forces
- Evolution of aesthetics: cross-cultural evidence for adaptive landscape preferences for lush environments abundant with resources and distastes for environments lacking resources and posing risks to survival
- People’s evolved sense of aesthetics includes fondness for lush foliage, blooming berries, and fresh water.
- Humans gravitate toward sheltered places where they can see without being seen. Many modern humans are currently shielded from these ancestral struggles with the forces of nature.
Struggles with other species
- Humans battle with other species upon whom they prey and who prey upon them
- Although most modern humans no longer struggle with dangerous species, the adaptations that evolved from those former struggles continue to be expressed in the modern world.
- People do not seek psychological treatment for car phobias, since they rarely occur, despite the fact that modern deaths by car accidents greatly exceed deaths by snake bite and falls from heights
Struggles with members of one’s own species
- Darwin recognized that humans posed dangers to other humans.
- The most dramatic battles occur in warfare, the life-and-death struggles that take the lives of dozens, hundreds, and sometimes thousands
- The close connection between warfare and reproduction reveals that the great struggles of life are sometimes closely connected.
- Those who succeed in the struggle for existence face a second Darwinian struggle—the battle for mates
Competition Among Males (Intrasexual Selection)
- Physical contests: the man who “has higher energy, perseverance, and courage . . . will generally become more eminent in every pursuit, and will gain the ascendancy”
- Dozens of tactics of attraction
men use to compete for mates - Men also sabotage their sexual rivals, another strategy in the struggle, as studies of derogation of competitors have
documented - Research also shows that some men physically dominate the rival in front of the woman they are attempting to attract, a form of public humiliation in which the victim’s social status suffers
Female Mate Choice
- Women universally prefer men with economic resources, masculine faces, health cues
- Women were far from passive
in the game of mating:
Male Mate Choice
- Man is largely, but by no means exclusively, influenced in
the choice of his wife by external appearance - Pointed to cultural practices such as tattoos, bodily adornments, and mutilations that some cultures found to enhance a woman’s attractiveness but which Westerners found physically repulsive
Competition Among Females
- Research verifies that women across all known cultures compete vigorously with other women to enhance their physical appearance
- Women’s same-sex battles hinge on whether they are pursuing a man for a long-term committed mateship or a short-term sexual encounter.
Mutual mate choice and mate value theory
- Those higher in mate value are better able to fulfill their mate preferences and enact preferred mating strategies
- Individuals
lower in mate value have fewer options and must “settle.” - Darwin thus anticipated “cross-character assortment,” where males and females couple with each other based on congruent elevation on different, but similarly valued, characteristics, resulting in assortment for overall mate value
Monumental Struggles of Life Missed By Darwin
- Conflicts within families
- Sexual conflict
R2
Of the Big 5, which are best understood? (in terms of underlying processes)
- Extraversion and Neuroticism; represent the primary manifestations in personality of sensitivity to reward and sensitivity to threat and punishment, respectively
Extraversion
- Linked to the tendency to experience positive emotions, which typically stem from experiences of reward or the promise of reward
- Extraversion encompasses an array of traits, such as assertiveness, sociability, and talkativeness, that appear to be linked to the approach tendencies that accompany sensitivity to reward.
Neuroticism
- Neuroticism is linked to the tendency to experience negative emotions, and includes such traits as anxiety, self-consciousness, and irritability.
Agreeableness
- Agreeableness appears to identify the collection of traits related to altruism: one’s concern for the needs, desires, and rights of others (as opposed to one’s enjoyment of others, which appears to be related primarily to Extraversion).
Conscientiousness
reflect the ability and tendency of individuals to inhibit or constrain impulses in order to follow rules or pursue nonimmediate goals.
This trait is linked to both academic and occupational success, as well as to behavior that promotes health and longevity.
Openness/Intellect
- Openness/Intellect appears to reflect the tendency to process abstract and perceptual information flexibly and effectively, and includes traits such as imagination, intellectual engagement, and aesthetic interest
- Openness/Intellect is the only Big Five trait to be consistently and positively associated with intelligence, a faculty that appears to be governed by brain systems that overlap substantially with the working memory network
Individual brain regions can serve multiple functions, and Conscientiousness and Openness/Intellect may reflect complementary but potentially conflicting functions of lateral PFC:
- Ensuring stable execution of plans and rules (associated with Conscientiousness)
- Manipulating abstract information in order to explore alternative possibilities (associated with Openness)
A greater-than-average volume of a specific brain structure may signify…
…greater-than-average power to carry out specific functions associated with that structure, on the assumption that larger populations of neurons can produce larger outputs and can therefore be more influential than smaller populations of neurons.
Smaller-than-average volume of a given structure might indicate
increased efficiency, or that the structure is streamlined to perform a particular function or set of functions.
Extraversion was associated with…
FINDINGS FROM PAPER
- the volume of medial orbitofrontal cortex.This region is involved in coding the reward values of stimuli
Neuroticism was associated with
- reduced volume in dorso-medial PFC and a segment of left medial temporal lobe including posterior hippocampus, and with increased volume in the mid-cingulate gyrus, including both gray and white matter.
- These associations are consistent with the theory that Neuroticism represents the primary manifestation in personality of sensitivity to threat and punishment, encompassing traits that involve negative emotion and emotional dysregulation
Agreeableness was associated with
- reduced volume in posterior left superior temporal sulcus and with increased volume in posterior cingulate cortex.
- The superior temporal sulcus is involved in the interpretation of other individuals’ actions and intentions on the basis of biological motion, a process that may be more efficient in individuals who score higher in Agreeableness.
- The posterior cingulate has been implicated in the process of understanding other individuals’ beliefs, a sophisticated, late-emerging component of theory of mind
