All Nature-Nurture Flashcards

how has conception of human vs nature changed?

throughout history we have tried to assert humans as above nature, but science, particularly Darwin's theory of evolution as applied to humans, puts us within it

darwin vs galton

darwin: objective description of evolution, galton: meaning of evolution for human individuals and societies

What was Galton's "genius"?

His genius was for inventing the tools he needed on the fly as he needed them (practically all of 20th century social science statistics)

eminence

the accumulation of wealth and professional accomplishment; Galton studied the familial clustering of this

In it's essence, 'Galtonism' is..

a tool-box full of ingenious empirical methods that have never been able to identify precisely what question they are supposed to answer

Heritability coefficients

ranges from 0-1, indicating how much more genetic something is than environmental; 1 is entirely genetic

what did daniel dennett say was Darwin's dangerous idea?

that design might not need a designer

What did Sam Harris define values as?

values are facts about the well-being of conscious creatures

Francis Collins

argued in favor of the existence of God from a somewhat scientific perspective, thought nature was too perfect not to be created by God

what made eugenics so appealing?

many non-scientific institutions failed to alleviate suffering, so maybe this new science can, as it had succeeded in other areas (agriculture)

what is the biological reason eugenics failed?

the causal pathways connecting genes to a tendency to violence or success in school are so complex and difficult to control that it is fundamentally impossible to manipulate genes to produce systematic changes in human behavior

what is the ethical reason eugenics failed?

genetics are not the only producers of outcome but so is the environment, and we cannot exercise as strict control over humans as we can over plants and farm animals

positive eugenics

rewarding "desirable" people who reproduce

polygenist viewpoint

idea that races are practically different species, being created by God separately. Major theories of race pre-Darwin rested on this conception

Galton's worst legacy, according to Turkheimer

the compulsion to represent racist, classist, and eugenic ideas as objective products of science

How were IQ tests used for eugenics?

IQ tests were administered to immigrants in order to weed out "unintelligent" ones

Buck v Bell

argued for (and was granted) the sterilization for the "feeble-minded" (sterilization of Carrie Buck)

What did Galton think the "place and duty of man" was?

the place and duty of man is the furtherance of the great scheme of evolution

What is an excuse that Galton made for eugenics (in a genocidal fashion)

People, especially "inferior" people, are going to die anyways

What did Galton think we should be breeding towards

"ideal typical form" which he came up with using composite images; should breed towards the median

pleiotropy

genes are connected, so trying to change one gene changes many others, possibly for a net negative. This is why trying to selectively breed for one gene is unwise

Jonny Anomaly viewpoint

there is no difference between eugenics and "genetic enhancement"; forcing people to breed in a certain way is wrong but the idea of breeding for "desirable" genetics is good

Robert Hutchins (on social science)

"a social scientist is a person who counts telephone poles"

variability

the spread of measurements around the central tendency

Galton's use of "regression"

the tendency of predictions to revert towards the average

Fisher (1918)

individual genes are discrete (mandelian) but the sums of many genes are continuous and normally distributed (biometry)

Binomial theorem

Used by Fisher as reconciliation of Mandelian genetics and biometry mathematically

Vg/Vp ratio

developed by Fisher to quantify the ratio of genetic variance to the phenotypic variance; 1 = entirely genetic based (correlative, where environment can easily be a confounding variable)

Barbara Burks

First adoption study, which correlated IQ of children adopted <1yo and their adopted parents, compared to a control of IQ correlated between related parents and children

Newman, Freeman, and Holzinger (1920s-30s)

twin intelligence studies (MZ vs DZ twins)

Where was h^2 first developed?

Sewall Wright's work with path analysis

Jay Lush

plant/animal breeding scientist who created the breeder's equation; also popularized using heritability in context of passing down traits genetically

The Breeder's Equation

the rate at which phenotypes change in response to selective breeding;

The greater the proportion of phenotypic variance that is "accounted for" by genetic variance, the faster the phenotype changes in response to selective breeding

what is heritability really (according to Lush)

not actually how much a phenotype is passed on, but the correlation of genetic to phenotypic differences

According to Fisher, how much variance in phenotype can be accounted for by environmental factors?

only 5%

The Tuskegee Experiment

African American men unknowingly infected with syphillis to study its natural progression. IRB instituted after this scandal

distribution

how do a set of numbers fall in comparison to each other

mean and variance on a distribution curve

mean is the height of the curve (typically), variance is the span of the curve

covariance

the joint distribution of 2 variables; how related are 2 things

3 ways to think about covariance

1. linear prediction model

2. as the slope of the regression line between two "standardized" variables (correlation)

3. intraclass correlations

regression to the mean

the predicted value of Y will always be closer to the mean of 0 than X

Linear prediction model

using line of best fit to "predict" what the value of Y will be using X

intraclass correlations

tells us how clustered things are within families (when it comes to genetics) — total variance = variance between families plus variance within families

Fisher's two goals

1. to interpret the results of biometry within the mendelian scheme

2. more exact analysis of human variability

after Fisher, genetics divided into 2 projects:

1. population and evolutionary genetics (biology)

2. nature-nurture (social science)

Sewall Wright

Created path analysis, a method for analyzing correlation matrices; inferring causation for correlations

t^2

ratio of genetic to environmental variance introduced by Holzinger (1937)

While eugenics became frowned upon after WWII, what Galtonian idea remained?

That genetic differences among people are correlated with phenotypic differences among people

what is heritability?

an intraclass correlation between genotypic and phenotypic differences

affirming the consequent

If P then Q, taken to mean if Q then P (not true). Seen here as causation implying correlation, but correlation does not imply causation

Eysneck Neuroticism in twins

criticized many genetic studies before it, compared MZ and DZ twin pairs on neuroticism, finding that MZ pairs were more correlated than DZ pairs were on their scores -- h^2 of 0.810

Dr. Viola Bernard

psychiatrist at columbia university involved in twin study where they purposefully separated twins, which was unethical

Dr. Peter Neubauer

scientist working on heritability who also was involved in separating twin study

hisoriometry (Galton)

correlation between the accomplishments of family members (eminence)

heritability (h^2)

correlation between "genotype" and "phenotype"; not a measure of "how genetic" something is

sampling error in heritability

sampling error is always present since the sample isnt the whole population.

what does heritability explicitly describe

describes a trait within a population; says nothing about individuals

why is the heritability of two arms 0?

it is hard to get a correlation with low variability. Since most people have two arms, the correlation between genetic variation is 0

phenylketonuria

condition where you can't digest a certain thing in some foods and its deadly if untreated, but treatment is eating a special diet and then theres no ill effects. Shows that just because something is highly genetic does not mean it is not malleable by the environment

how did Galton use twins for studies?

assume that twins are somehow similar genetically, study how they become different environmentally

Curtis Merriman (1928)

first quasi-modern twin study of intelligence using Stanford-Binet IQ test, finding correlations aroun 0.9 for IQ scores and teacher ratings

When were modern twin studies developed

in the 1920s

"peas in a pod" questionaire

measure used before easy genetic testing to help figure identical vs fraternal twins. Has questions like "do you often confuse them?"; Actually has high validity

Iowa Studies of Skodak and Skeels

poor children adopted into non-poor families had higher IQs than their mothers, but their IQ correlated w/ their bio mom 0.31 and 0 w/ education of adopted parents

what is the ACE model

A= heritability; C = common environment; E = non-shared environment. Proportion of difference that is "explained by" each of these things

A (heritability) formula

2(rMZ-rDZ)

C (shared environment) formula

2(rDZ) - rMZ

E (non-shared environment) formula

1 - rMZ

What is C when it is on a graph

it is the Y intercept

why is a negative value in ACE a "violation"

it means that rDZ > rMZ, which is not expected to be true

equal environment assumption

we assume C for MZ = C for DZ, but maybe this isn't the case

Cyril Burt and Hans Eysenck

2 theorists of human individual differences who were Galtonian and Eugenicist in outlook, perpetuating these frames in the post-WWII era

Eysenck big 3 model

extraversion, neuroticism, and psychoticism

proband method in schizophrenia twin study

seek schizophrenic patients (the probands) and ask them if they are twins (rather than go through twins and ask if either has schizophrenia)

two aspects of adoption studies

individual differences: what is a better predictor of adopted child's outcome, biological parents or adoptive parents?

group differences: differences in average outcome in adopted children compared to either a) biological parents b) non-adopted siblings

selective placement

issue with adoption studies where, in the real world, adoption is not conducted at random, children were often matched by ethnicity or social class

restriction of range

a statistical phenomenon that makes it hard to detect relations with variables that don't vary much; range is restricted in adoption studies bc most adoptive homes are middle-class or better

main conclusion of the Three Laws of Behav. Genetics paper

Genotype is a more systematic source of variability than environment, but this is a primarily methodological limit. Environment is too idiosyncratic to be adequately studied.

Objective vs effective nonshared environment

objective: an event is nonshared if it is expereinced by only one sibling in a family, regardless of the consequences it produces

effective: an environmental event is non-shared if it makes siblings different rather than similar, regardless of whether it was experienced by one or both of them

How do Plomin and Daniels define nonshared environment?

they think that the nonshared environment as an effectively defined variance can be explained by objectively nonshared environmental events

three laws of behavior genetics

1. everything is heritable

2. families contribute a relatively small portion of the variability in genetically informed studies

3. most variability in human behavior cannot be predicted from genes or environment

polygeny

many genes contribute

pleiotropy

each gene has multiple effects

passive rGE (gene-environment correlation)

parents provide both the genes and the environment

evocative rGE

an individual's heritable traits elicit specific reactions from other

active rGE ("niche-picking")

individuals actively seek out and select environments that complement their genetic tendencies

why would C be 0?

DZ twins become more different as they get older, and MZ twins stay roughly the same in similarity

second law complication: between- and within-group analyses

within-group differences appear genetic, whereas between-group differences appear environmental

since C is small and E is large…

most important environmental effects must be of the (objectively) nonshared variety

three step research program (plomin + daniels)

1. quantify within family environment

2. identify specific within family variables

3. causal associations between Within-Family E and Behavior

how is E unsystematic

it is the unsystematic result of all the developmental complexities that follow from individual genes and individual environmental events

stochastic processes

procedural development that comes across as "random" (not clearly mapped by genes); randomness is overlooked in studying genetics

The Gloomy Prospect

that nonshared environment is unsystematic, idiosyncratic, and/or made up of serendipitous events

outcome heritability

The correlational observation that people who start out more genetically similar wind up more phenotypically similar

essence heritability

Genetic processes in which there is a homology between genetic structures and phenotypic outcomes, with a mechanism that links them

GxE vs rGE

GxE is when genes and environments depend on each other, rGE is when genes and environment correlate

Scarr-Rowe interaction

heritability of intelligence depends on thrings such as SES

what is Turkheimer's conclusions about the findings that divorce is genetic

"The problem turns out to be not in the validity of these findings, but instead in their ubiquity" (p. 77)

quasi-experiments

experiments without random assignment to conditions, typically involving longitudinal data or interrupted time series; trying to get at causality

how does longitudinal data imply causality

w/ time, you can know which direction causation is (which came first), but not what certain factors are causal