Week 3 - Genetics, evolution and personality Flashcards
W. H. Sheldon (1942) expanded the idea from categories to dimensions and looked at normal personality. He believed each quality relates to one of three layers of the embryo. For that reason, he named them after the layers:
Endomorphy - is the tendency toward plumpness (reflecting digestion). Endomorphs are soft and round.
Mesomorphy - is the tendency toward muscularity (reflecting predominance of bone and muscle). Mesomorphs are rectangular, hard, and strong.
Ectomorphy - is the tendency toward thinness (reflecting the skin and nervous system). Ectomorphs are delicate and frail, easily overwhelmed by stimulation.
Behavioral genetics
This is the study of genetic influences on behavioral qualities, including personality
Heritability estimate
This index represents the amount of variability in the population that’s accounted for by inheritance in the trait under consideration. The higher the heritability, the stronger the evidence that genes matter.
temperament (1984) df + 3
refers to an inherited personality trait present in early childhood.
3: activity level, sociability, and emotionality.
Activity level
is the person’s output of energy or behavior. It has two highly correlated aspects: vigor (the intensity of behavior) and tempo (its speed). People high in activity level prefer high-intensity, fast-paced activities. Those lower in activity level take a more leisurely approach to things.
Sociability
is the tendency to prefer being with other people, rather than alone. It’s a desire for sharing activities, along with the social responsiveness and stimulation that are part of interaction.
Emotionality
is the tendency to become emotionally aroused—easily and intensely—in upsetting situations.
Approach temperament
The temperamental tendency to approach rewards.
Avoidance temperament
The temperamental tendency to avoid threats.
Effortful control
A tendency to be focused, restrained, and planful.
Which big 5 is approach temperament similar to?
Extraversion, and in part agreeableness
(Some people think extraversion is about approaching social rewards)
Which big 5 is effortful control temperament similar to?
Conscientiousness
Which big 5 is emotionality/avoidance temperament similar to?
Neuroticism
Which big 5 is intelligence temperament similar to?
Openness to experience
(it often is referred to as intelligence, as it’s one of the more elusive of the big 5).
Intel = Genetically influenced, and its effects on behavior are broad, manifest early in life, and continue throughout the life span (making it a solid temperament)
Nonshared environmental effect
The environment seems to affect personality mostly by making twins different, rather than the same
Name 3 contexts where a correlation between environment and heritability is likely to occur
When an inherited inclination leads you towards an environment that encourages that inclination to flourish
Sometimes, the impact comes from outsiders’ genes, as when parents’ genetic makeup leads them to create particular environments for their children (e.g. the IQ Vocab / education chart)
Sometimes, it comes when people’s genetic makeup affects the responses they induce from people around them.
Gene expression
when the gene engages in the processes that create a protein.
gene expression is not the same throughout the body. Gene expression varies by region and type of cell involved (e.g., brain cells, blood cells).
methylation
The attachment of methyl chemical groups to what’s called the gene’s promoter region (its “on” switch). When there’s more methylation, there’s less gene expression. This doesn’t involve a change in the gene itself. For that reason, it’s called an epigenetic effect (which in this context means “in addition to genetic”). Methylation can be affected by stress level and even by diet
Two labels for the view that humans are a product of evolution leads to the possibility that ancient evolutionary processes have a major influence on present-day human behavior.
sociobiology and evolutionary psychology
directional selection
a shift toward a higher proportion of the adaptive allele in the population’s next generation.
stabilizing selection
Evolution in which intermediate values of a dimension are most adaptive.
e.g. It’s important for people to have some sociability, because humans are such a social species. Having too little sociability isn’t adaptive. But neither is it adaptive to have too much sociability. A person with extremely high sociability can hardly bear to be alone, and life sometimes requires people to be alone.
Inclusive fitness
The passing on of genes through the survival of relatives.
Genetic similarity theory
By making you attracted to someone with genes like yours, your genes increase the odds that genes like themselves will be copied (from one parent or both) into a new person, thus passing into the next generation.
assortative mating
The general idea that people choose mates on the basis of particular characteristics
