Intelligence Project Flashcards
Threshold Hypothesis
Specific to creativity, a certain level of intelligence is necessary but not sufficient for creativity, no correlation at high levels. Evidence is mixed.
Perfect pitch
Thought to be a 1 in 10,000 occurrence, it is more common in people speaking tonal languages and was taught to every one of the children in a 1.5 year study
Growth mindset
Belief that intelligence can be changed through effort. Evidence that this can be changed is weak.
Grit
Ability to persevere in the face of challenges. Evidence that this can be changed is weak.
Preterm births
Lead to lower scores on cognitive tests, math tests, reading tests, behavior assessments, motor control, etc
Some examples of human progress
Marathon record dropped by 30%, Olympic dives recommended banned now competed by 10 year olds, Steve Faloon’s memory feats
Constrained vs unconstrained skills
Constrained are finite - letters of the alphabet, basic letter-sound correspondence. Unconstrained is stuff like knowledge. Unconstrained more correlated with outside variables.
Flynn Effect
The gradual but substantial and long-sustained increase in IQ scores over time across the world. Some evidence of reversal in northern Europe.
g-loading
How much a particular skill is correlated with the hypothetical general intelligence g
Deliberate practice
Explains from 0% to 26% of variability in Macnamara et al meta-analysis, higher values for more predictable domains
Polygenic index vs college completion
Similar explanatory power to family income
GWAS
Genome-wide association study, used to create a polygenic index
Polygenic index percent of outcomes explained
Typically 10-15%, a bit more than income-higher education, a bit less than height-weight
Rough heritability of intelligence as measured by IQ (Ritchie)
50%
Counterfactual: why genetic causal claims can be confusing
If a society refused to send redheads to school, genes for red hair would seem to be associated with educational outcomes
Positive manifold
Broad trend that different measures of cognitive ability tend to be highly correlated, seen as evidence of underlying g
Fluid vs crystallized intelligence
Fluid more connected to reasoning and working memory, more correlated with intelligence, doesn’t change much. Crystallized more connected to knowledge and long-term memory, grows over time.
Matthew Effect
Those who start with an advantage accumulate more advantage over time
Flynn Effect differential
The gains are largely due to increases at the bottom of the spectrum
Genetic effects on differences measured at age 10 months
None
Heritability of executive function
Nearly 100%
Outcome of chess instruction
Kids get better at chess, null on academic and non-cognitive outcomes
Percent of variance in learning attributable to teachers/schools (Detterman)
10%
Average effect size in education RCTs, Dietrichson
0.06
Summary of pre-k research (DeBoer)
Mixed bag, more recent and randomized studies show much smaller (sometimes negative) effects
Throughout childhood, genetic influences on cognitive ability
Increase
Male/female differences in polygenic predictions of educational attainment historically
Increased access to education increased genetic inequality
Examples of interventions that narrow genetic inequality
Association between genetics and obesity reduced, association between genetics and alcoholism eliminate, association between genetics and math courses taken reduced
Raven’s matrices and working memory
When under time pressure, working memory and fluid reasoning are the same. They diverge a bit without time pressure
Fluid intelligence vs crystallized intelligence
Fluid is more correlated with g and seems to be mostly working memory + processing speed. Crystallized is more about long-term memory.
Executive function interventions
Rarely show results in follow-up assessment
Executive function is maybe just (Loffler)
Processing speed
Polygenic score/learning rate effect (Youn et al, Harden)
Practice seems to narrow genetic effects
Cognitive components of athletics
Pattern recognition in volleyball/baseball accounts for much of skill differences, baseball players can’t hit a softball pitch
Ackerman’s study
Air traffic control simulation, larger ability correlations in the arrivals condition, individual differences increase with practice in that condition (?)
Modern evidence that practice widens gaps
Zerr et al, Lithuanian words study. Lots of potential confounders but still really interesting.
Three Laws of Behavioral Genetics (Turkheimer)
All behavioral traits are heritable, effect of genes is larger than the effect of family, most variation is stuff besides genes and families
Flynn Effect fluid vs crystallized
No effect on processing speed - seems like it’s more about crystallized knowledge
Positive manifold or negative manifold?
The positive manifold increases with lower IQ, and increases as children age (Gusev)
g-loading is highest on
Culturally loaded subtests (Kan et al 2013)
SES-IQ association
None at 10 months, gradually grows stronger over time (Gusev)
Mutualist model of intelligence
Data suggests a bidirectional feedback loop between fluid and crystallized intelligence, for instance matrix reasoning and vocabulary
Most g-loaded IQ subtests
Most culturally loaded, i.e. vocabulary, knowledge
A million little nudges evidence
Things like preschool fade, but adoption matters a ton. No neurological basis for intelligence. Cultural loadings for g. EEA violation for twin studies.
Quincunx model for missing heritability
If i.e. divorce is a bin in a quincunx, a pin can have a bias towards that bin but still produce nothing in a GWAS because the system is so complex
Adoption studies
Not a strong correlation between adopter IQ and adoptee IQ, but a large increase in adoptee IQ
