cog 3/11

Intelligence, cognitive control 

• Measuring intelligence 

• Cognitive control / executive function 

Measuring intelligence 

• Intelligence - the ability to reason, plan, solve problems, think abstractly comprehend complex ideas, learn quickly, and learn from experience 

  • Not the same as book learning or test taking smarts 

  • An ability crucial for catching on or making sense of things or figuring out what to do 

  • Solving problems - knowing how to solve problems - they know stuff bc they have pipe knowledge 

  • Some version that acknowledges solving problems 

• Crystallized intelligence - acquired knowledge, including verbal knowledge and expertise in a subject 

• Fluid intelligence - the ability to deal with new and unusual problems 

  • There are other abilities that make ppl intelligent 

  • Big difference in having knowledge and do the thinking (fluid intelligence part) 

• Intellectual development - 

  • Late adulthood - have more crystallized intelligence, but less fluid intelligence (more knowledge collected over time like stronger vocabulary) 

  • Early adulthood - less crystallized intelligence, but more fluid intelligence (faster at solving problems) 

• Large study - had ppl ages 20 to 80

  • U will know more words as you grow older 

  • Mental speed, fluid intelligence, and working memory are all at a decline as you grow older (on average) 

• All these tasks - go together - this is not obvious

• Origin of thinking about things - measuring intelligence - the beginnings 

  • Universal elementary education - 1904 in france 

    • Farmer kids and rich kids did not know the same information 

    • How do we identify kids who need extra help? 

  • Designed first intelligence tests (copy a drawing, repeat digits, recognize coins, explain why a statement did not make sense) 

    • Used it to identify kids who needed help 

    • Tests are there to see which kids are falling behind 

• We cannot ask ppl to draw coins 

  • The kind of thing that is about fluid intelligence (solving novel problems) 

    • To isolate fluid intelligence from crystallized - they have diff tasks 

    • Ex - which pieces go together to finish this puzzle? 

Usually normalized with a mean of 100 and a standard deviation of 15 

• Forced standard deviation of 15 on them 

• Took actual raw scores and applied normal distribution on them 

• If average person only gets 25 out of 35 right - they stretch out the distribution 

What makes something a useful measure of individual differences? 

• Reliable - same score on two occasions (if i give u the same test on two occasions you will generally get the same score) 

• Valid - measures what it is supposed to measure (the ability to solve problems in abstract situations) 

  • Finding ppl who are exceptional in a given area 

  • Understanding measures of individuals 

  • Personality measures - are trying to be stable individual measures - reliable and valid 

IQ scores - reliability 

• IQ is a very reliable measure about as good as all personality and other individual difference measures 

• Test retest reliability very high (around .70 or .80) 

• SAT is very reliable 

• Does this reliably measure ppl around me? 

  • Measurement error - 

    • Fatigue, sickness, stress differences on the day of 

    • Test taking environment (noise) 

    • Item differences (ex - different questions) 

  • Environmental changes during crucial periods of development (like teen years) 

  • Practice effects 

  • These tests are pretty reliable despite the errors 

How do u measure validity? 

• Tells us something about how good you are at abstract reasoning 

• Valid for what? - IQ is not the worth of an individual 

  • Valid for what? - validity of IQ tests as a measure of fluid intelligence amounts to whether we can use it to predict how well u solve abstract novel problems in other situations 

    • Researchers are interested in g as a measure of other aspects of cognitive control 

• Measures of what this predicts - what makes it valid - is trying to be valid 

  • Single largest sum in psychology 

  • Validity as a measure of fluid intelligence 

  • IQ predicts job performance 

    • Intellectually complex professions - IQ predicts 36 to 64% of variance in success 

    • Assembly line job performance - products only 4% of variance in success 

    • Academic success - IQ predicts about 25% to 40% of variance in school (there are so many factors which is why the percentage variance is so high) 

      • Just bc u are intelligent does not naturally mean u will get good grades 

        • U have to show up to class and actually study the material 

      • grades - we want to teach ppl how to learn and critically think 

    • Later life outcome - 

      • Even within the same middle class family - IQ still predicts 10% of variance in income in later life 

      • Take all ppl in your sample and plot all incomes - u can predict where in that sample they fall 

The flynn effect 

• Decade and IQ relative to 1920 

• If we gave u the same test in 1920 - more than 50% of population would test above the 50th percentile 

• Tests have to keep getting harder and harder 

  • Has plateaued in some regions 

  • What is this thing measuring? - in 1960s everyone in america on average - has changed as the world has evolved 

• Small gains - vocab, general knowledge, arithmetic 

• Large gains - abstract reasoning (ex - raven’s matrices) 

• We live in a more abstract world? 

• When we watch TV now there are 7 plots 

  • Back then there was one very simple plot in a TV show 

• The world is now more complicated and complex 

• We live in more complicated worlds - working demands are harder 

  • We are faced w more challenges and live further detached from things 

  • We learn about animals and biological trees, etc 

  • We have more abstract knowledge of the world 

General gains in health 

• A lot of ppl had poor scores bc they were in poor health 

• Giving them all battery of health and mental tests 

• There is no selection bias - we are plotting general ability 

  • Height is plotted here - they look very similar 

  • The world got taller - general health - we have more access to healthcare and food and resources than back in the day

  • We have all gotten healthier and this makes us able to live in a more complex world 

IQ scores - measures of more than just abstract reasoning

• Higher IQ is associated w longer life expectancy, lower disease risk and better health behaviors 

• IQ predicts a lower risk of accidental death, possibly due to better decision making 

• Overall - IQ test scores correlate w GPA in HS and college, job success, salary, stability in marriage, staying out of jail, longevity 

  • The higher someone’s IQ the less likely they are to get divorced 

• If IQ was causally related to access to resources (ppl came from more money) 

• Cognitive control - everything correlates 

• Inhibition, suppression of things 

Can we think of fluid intelligence as a single thing? G and Gf as constructs 

• G - general intelligence 

• Gf - general fluid intelligence 

• Ppl who are good at one of these things tend to also be good at other of these things 

  • How good r u at auditory perception - if u test good in auditory → will also test better in vocab tests 

  • Ppl score better in school do better in sports - on average some ppl perform better than others 

• Anything cognitive - they are all correlated 

• There is some kind of g factor - this makes u more or less good at certain things 

  • All of these tasks are related to one another - g factor - some ppl have more or less and this makes us better at certain things 

  • Gf - general fluid intelligence 

General vs specialized intelligence 

• Most modern IQ tests (ex - wechsler, stanford binet aim to measure g by including many subcomponents) 

• There are some general facts and aim to measure gf 

  • The thing that is in common - gf and g - some are better at spatial or verbal intelligence 

  • If u give ppl an intelligence test - some ppl are generally better at everything than others 

    • Why are u better at all of these tests? - ppl have many hypotheses - processing speed - many ppl may have a faster processing speed (if u are faster at processing stuff u are just better overall) 

      • Light on table and as soon as light flashes u press button (1,000 trials) 

      • Ppl w faster reaction times score higher on IQ tests - this makes the person better at solving abstract problems 

      • Infant habituation - the same stimulus is shown, infants who get bored faster means they have higher IQ - processing speed - some brains just process things faster than other brains and score higher on all these tests 

    • Attention and attentional filtering - red squares and blue squares - some ppl remember the blue ones even tho they are told not to 

    • Working memory capacity - ppl that can hold in mind more things 

      • These correlate highly w intelligence measures 

      • Internal buffers 

    • Cognitive control - ex - ease of engaging system 2) 

      • Some tasks demand system 2 

      • Some ppl tend to be more reflexive 

      • Inhibition - suppressing ur initial response to things 

      • Not eating the marshmallow correlates to intelligence 

• Why is it that the same ppl are better at all the things? - 

  • There does not have to be the same causal answers 

  • Ppl like to think  about it statistically 

Working memory correlations 

• Gf - all correlate w working memory capacity 

• All of these tasks correlate w each other 

• Even tho these tasks are very different - they all correlate w each other 

No evidence of intelligence improvement after working memory training: a randomized placebo controlled study 

Cognitive control / executive functioning 

• Cognitive control - using system 2 at the right time 

• Central executive - what u want to hold in mind

• We use tasks that gain reflexive training 

• A bat and a ball cost $1.10 in toral 

  • The bat costs $1 more than the ball. How much does ball cost? - 5 cents 

• If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets? 

• In a lake, there is a patch of lily padsl. Every day, the patch doubles in size. If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half of the lake? 

• Everyone has an instinctual answer to everything 

  • When u see a pic of a grandma - does this person have kids? - we dont know if this old lady has kids - we just intuitively say yes 

Ability to stop intuitive responses 

• The word orange but it is written in purple ink

• Respond only to the direction of the middle arrow, ignore the flanker arrows (hard to suppress intuitive thoughts) 

Broad hearing of executive function and cognitive control 

• Inhibit - stopping and impulsive act 

  • Being able to think about the consequences before acting 

• Shift - transitioning from one task to another 

  • Preferred to non preferred activity 

  • Letting go of a specific interest 

All prefrontal cortex functions 

• Prefrontal cortex - all things we just talked abt relate to the prefrontal cortex 

  • Humans are more intelligent than chimpanzees 

  • Intelligence is a small part of life 

  • Phineas gage - he built a railroad and the rod went straight through his skull - never loss consciousness & had huge long term issues - 

    • Before the accident he was responsible, caring, and well behaved 

    • But after the accident - he became erratic, profane, and impatient 

• Something about prefrontal cortex is related to intelligence 

Tools of the mind 

• Having better health - makes u better equipped to learn 

• Preschool program improves cognitive control 

• Low income families - most malleable families 

  • Statue game - everyone freezes and first person who moves loses 

  • Scaffolding - inhibiting yourself - designed to make u not want to make the thing u want to do 

• Flanker task - direction of inside arrow 

• Reverse flanker task - direction of outside arrow 

  • Kids were Playing statue game in class was better at flanker arrow task 

• Fluid intelligence - measured w IQ, has both reliability and validity 

• Hierarchical - both g and gf and specific abilities 

• Ability to do abstract reasoning problems (fluid intelligence) is related to speed of processing 

Heritability, nature vs nurture 

• Underlying g and gf factors 

• Processing speed 

• Attention and attentional 

Roots of intelligence 

• Behaviioral genetics - studying twins and adoption 

  • Compare twins and see how intelligence effects intelligence 

  • Monozygotic twins - identical twins - identical genes 

  • Fraternal twins - half of the same genes

• Can look at twins raised apart vs twins raised together

  • Sibs raised apart vs together 

• Heritability differences - 

  • 0 means no variance due to genetics 

  • 1 means all variance due to genetics 

  • .30 means 30% is due to genetic differences 

• Same strains of corn in two bags 

  • Plant all in same field in iowa - difference in environment is small - high heritability score 

  • Half corn in desert in nevada and half in iowa - 

    • Iowa corn looks great - large environmental differences make genetic differences a small part of the total variance 

• Heritable does not mean innate 

  • Innate traits can have zero heritabiluty (ex -number of legs is close to 0 heritability - very little variance and most of it environmental) 

  • Heritable traits can be environmentally determined 

• If u measure IQ 

  • Identical twins have .9 correlation 

  • Fraternal twins have .8 correlation 

  • Sibs raised together a bit lower than twins 

  • Unrelated individuals in diff households - no correlation 

• There is a very strong correlation w intelligence and genetics 

• Genes - 50% 

• Shared environment - 0-10% 

• Unique environment - 50% 

• True for intelligent, brain structure, schizophrenia, personality disorders, memory, success of family relationships, pain tolerance 

• Is intelligence fixed? 

  • If everyone was raised in same house 

    • In poverty the degree of IQ resemblance is the same for identical twins and fraternal - genes matter much less for shaping a person’s intelligence in this environment 

  • Middle class and upper class ppl in these studies all have environments that are similarly 

Environmental effects are easy to see in the negative direction - ex lead exposure decreases IQ 

•  On average - most of variation in upper middle class america - most of it is genetic 

Summary of intelligence 

• Approximately 50% heritable (not the same as 50% innate but definite environmental influences)