Intelligence Flashcards
What is intelligence?
Sternberg and Detterman (1986) show psychological definitions commonly include:
- Higher level abilities (e.g., abstract reasoning)
- Valued by culture
- Executive processes
- “mental abilities necessary for adaption to, as well as sharing and selection, of any environmental context”
How is intelligence measured?
IQ = a test which is standardised to a mean score of 100 and standard deviation of 15
Norming involves administering IQ test to a representative sample of a population to obtain norms or referential scores for different sub-groups (e.g., age groups).
what are the different branches of IQ (cognitive abilities) research (Deary & Caryl, 1997)
- real life impact = educational achievements, employment success, life task outcomes
- cognitive = reaction times, inspection time
- biological = brain event potentials, nerve conduction velocity, brain size, functional brain scanning
- structure of intelligence
Structure of intelligence: Psychometric IQ
- has a hierarchical structure
- general intelligence is split into learnt factors and biological potential
- learnt includes spelling, writing and oral style
- biological splits into reading speed, piagetian reasoning, sequential and inductive reasoning
what is fluid intelligence? (Gf)
- Focuses on process independent of content or knowledge domain ie. not based on prior knowledge
- includes executive control and working memory tasks (may also be referred to as fluid cognition).
- Seen as biologically instantiated in the pre-frontal cortex.
- Declines in later life (Bugg et al., 2006)
what is crystal intelligence? (Gc)
- Gc is a product of Gf →Investment theory (Cattel).
- Gc test: vocabulary etc represent acquired knowledge.
- Knowledge (acquired) increases over lifetime.
How does Gc and Gf change over a lifetime?
- conventional wisdom is that fluid intelligence peaks relatively early in life and then declines
- This challenged by more current research suggesting heterogenous effects on different cognition domains (e.g. Hartshone and Germine, 2015)
are genetics heritable?
- heritability estimates from .42 to .62 (up to .80)
- This means between 48% and potentially up to 80% of the variability in IQ scores is attributed to genetic variation?
- but problem of heritability gap as assumes genes are independent of the environment (Plomin and Deary, 2015)
Heritability of g: group differences controversies
- Behavioural genetics assumes independence of genes and environment
- Also tends to assume that fluid intelligence is fixed and crystallised intelligence less so
- Spearman’s hypothesis
what is Spearman’s hypotheiss?
- Noticed people’s performance of a cognitive test was correlated with their performance on other comparable cognitive tests. Hence, he proposed a common latent factor g that broadly represents cognitive capability
- Noticed that the more strongly a test correlated with IQ, the wider the difference in Black and White American’s performance on the test
- Hypothesised that Black-White differences on tests of cognitive ability correlate positively with g-loading
- extended by other authoes (e.g., Arthur Jensen, Charles Murray, J.P Rutherford, Hans Eyesneck) to suggest that racial IQ differences are genetic in origin
Eysenck’s hereditarian views on race
- Eysenck’s hereditarian views on race and intelligence were highly controversial.
- Current research has confirmed that IQ is heritable.
- Research has found no significant genetic determination of racial differences in IQ.
- Group differences in IQ may be entirely explained by envt’l factors
what is the Flynn effect?
- Generation rise in IQ by average of 10 percentage points (range 5 – 20 points)
- This is seen across at least 14 countries.
- It is more substantial for Gf than Gc.
- Stronger among adults than children.
- Highest in the Netherlands, below average in the UK, ceased in Sweden and reversed in Norway.
what environmental changes produce large changes in IQ?
- Social multipliers
- Averaging
- Gene-environment matching
how do social multipliers contribute to an IQ increase? (Rindermann et al., 2017)
- Internet and access to information
- TV?
- Gaming (reaction times and speed)?
- Education
- Group learning and studying
- Rising standards of living
- Better nutrition
how does gene environment matching contribute to an IQ increase?
gene-environment correlation
- people seek out environments that match their phenotype
- these processes by which the ability and the environment are matched produces increases on that initial ability
- Thus, environment increases genetic/biological ability