Intelligence+and+Research+on+intelligence+and+some+concluding+thoughts+on+intelligence


 * < ==__Term__== || ==**__Definition__**== ||
 * < Meta-Analysis || The statistical synthesis of the data from a set of comparable studies of a problem that yields a quantitative summary of the pooled results. ||
 * < Minnesota Twin Study || (Bouchard et al. 1990) A longitudinal study that has been going on since 1979 in which identical twins raised apart (MZAs) are compared to identical twins raised together (MZTs). ||
 * < Less Effort Hypothesis || Those with higher IQs use less energy to think that those with lower IQs. ||



**__ INTELLIGENCE __**

//IQ - tests which can indicate one's genetically endowed intellectual potential//

- developed an intelligence tests - improve French education system
 * Alfred Binet (pioneer in intelligence research at the beginning of the 20th century)**

inherited / result of environmental stimuli
 * Main controversies regarding intelligence**

1) Poverty has an influence on the development of the child's intelligence. 2) (1994) Harvard professor, Richard J. Herrnstein - Published //The Bell Curve :// - debate about genes/environment influences on ethnic differences remains unresolved
 * Research**

- What is it? - How can it be measured?
 * Nature of intelligence :**

- early intelligence theorist - found that students performance across different subjects was positively correlated - general intelligence factor : basis of all intelligence = "g" factor
 * Charles Spearman**

**Modern Intelligence Tests :**



- assess "g" factor

- not looking at specific school subjects



Where does "g" come from?

__ RESEARCH ON INTELLIGENCE __

- 111 studies of IQ correlations - sample: siblings from around the world - **meta-analysis** - results: closer kinship = higher correlation of IQ
 * Bouchard and McGue (1981)**

- research on identical twins - 100% percent genetic relationship - brought up separately from birth - grown up in different environments ... any similarity between their IQs = due to genetics rather than enviornment
 * Role of Genetics in Intelligence:**



__Minnesota Twin Study__
- Bouchard et al. 1990 - longitudinal study since 1979 - Identical twins raised apart (MZAs) compared to identical twins raised together (MZTs) - most cross-cultural study - sample: all over the world - mean age : 41 years old (at the start of the study) - almost all research on adolescents - procedure: about 50 hours of testing and interviews Concordance rate of intelligence from study - heritability of about 70% = 70% of intelligence can be from genetic inheritance = 30% of intelligence may be from other factors
 * Same person tested twice || 87% ||
 * Identical twins reared together || 86% ||
 * Identical twins reared apart || 76% ||
 * Fraternal twins reared togher || 55% ||
 * Biological siblings reared together || 47% ||

__**Criticisms of the Minnesota Twin Study**__ - Bouchard relied on media coverage to recruit participants - There are some ethical concerns about the way he reunited the twins - There was no adequate control to establish the frequency of contact between the wins prior to the study - We cannot assume that twins who are raised together experience the same enviornment = "equal enviornment assumption"

__**Adoption Studies**__ - intelligence of the adopted child is correlated with the intelligence of the adoptive parent - no biological link = environmental influences should be evident

- parents who raised both adopted and natural children Assumption: all children had the same upbringing + same enviornment + same parents - findings: no significant difference in IQ correlation - Most of the sample: parents were wealthy, white, and middle class, with high IQs - adopted children were poor, low-class backgrounds, with lower IQ parents
 * Scarr and Weinberg (1977) and Horn et al. (1979)**

- well-controlled adoption studies in France - findings: transferring an infant from a low socio-economic status family to a home with high socio-economic status parents = improves childhood IQ by 12-16 points ... intelligence has a lot to do with the enviornment + genetics = enriched environment may raise the IQ of children
 * Wahlstein (1997)**

__ CONCLUDING THOUGHTS ON INTELLIGENCE __ What is intelligence? Is it only based on knowledge? Or is it related to our ability to solve problems? Hainer et al. (1988) - PET scan study When solving a reasoning problem: individuals with a high IQ : lower metabolic rate individuals with lower IQ : higher metabolic rate - only seen in problem solving - not in data recall = higher IQ's use less energy to think = **less effort hypothesis** Plomin and Petrill (1997)  - correlation between parent and child IQs change over time - 4 to 6 years = 40% correlation - early adulthood = 60% - older adults = 80% ... genetic disposition pushes us towards environments that accentuate that disposition ... increased heritability throughout the lifespan - Socio-economic class = one of the most important environmental factors: development of intelligence - Poverty (not genetic inferiority) - key to understanding differences in intelligence Flynn effect - rise of average scores on intelligence tests - most parts of the world - in the last century James R. Flynn - document this to create awareness of its implications  Ulric Neisser - article in //The American Scientist// (1997)  - average mean scores on IQ tests are increasing by about 3 points every 10 years

- higher increase in abstract-reasoning ability - cause: unknown ... possibly: - real increase in intelligence - increasing ability to crack intelligence tests - better nutrition - improved schooling - different child-rearing practices - increased use of technology in modern life Neisser : living in a highly visual environment may play an important role in the rise of IQ scores.

Short Answer Question Explain How Research on Intelligence Helps the Study of the Influences of Genetic and Environmental Factors

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