PSYC1002 Flashcards
Mental abilities
What does mental ability mean?
the capacity to perform the higher mental processes of reasoning, remembering, understanding and problem solving
How do you measure mental abilities?
• Individual differences approach is how mental abilities are studied and measured, and see what gives the rise of individual resources
o First step to measuring is to define what is being measured
o Second step is to think about what the behaviour influenced by that trait looks like
Devise tests to look at intelligence, and look at the score to determine future performance
What are the different types of intelligence?
- Analytical intelligence
- Practical intelligence
- Emotional intelligence
What is analytic intelligence?
the ability typically measured by intelligence tests and crucial for academic success
What is practical intelligence?
the ability to solve everyday problems through skilled reasoning that relies on tacit knowledge
What is emotional intelligence?
the ability to understand one’s own emotions and others’ and also the ability to control one’s emotions when appropriate
o Ability to perceive emotions accurately
o Ability to use emotions to facilitate thinking and reasoning
o Ability to understand emotions, including use of language
o Manage emotion in oneself and others
o Measured by the MSCEIT test
What is a manifest variable?
what we can see
What is a latent variable?
what we infer- constructs
What is the definition of a construct?
Theoretical terms which cannot be directly observed, but are assumed to exist because they give rise to measurable phenomena
Why are constructs useful?
o Description and explanation of behavioural and performance data
o Basis for prediction of behaviour
What are constructs defined by?
Empirical indicators
Relationships to other constructs
• Correlation between intelligence and personality- if they correlate tightly, they might be the same thing
Network of constructs (nomological network) becomes the basis of the theory
What is the implicit intelligence theory?
informal definitions of intelligence and are based on beliefs
What do entity theorists believe about mental abilities?
Abilities are fixed
What do incremental theorists believe about mental abilities?
Abilities are changeable
What did Blackwell, Trzesniewski and Dweck look at?
Looked at the learning trajectories of 7th graders
The ones that believed that intelligence is malleable (incremental theory) predicted an upward trajectory in grades over two years of high school, while a belief that intelligence is fixed (entity theory) predicted a flat trajectory
Concluded that an incremental theory led to more effort and a more positive response to failure
What did Sternberg do?
What behaviours show
• Intelligence/unintelligence
• Academic intelligence
• Everyday intelligence
Came up with three factors
• Verbal intelligence
o Good vocabulary, converses easily on lots of subjects
• Problem solving
o Makes good decision, poses problem in optimal way, plans ahead
• Practical intelligence
o Sizes up situation well, determines how to achieve goals, displays an interest in the world at large
Intelligence relates to success in cognitively demanding tasks but not necessarily highly related
What is explicit intelligence theory?
use data collected from people performing tasks that require intelligent cognition
What are steps in testing the explicit intelligence theory?
Start off with a hypothesis
Then test it
Then look at how performance on that test correlates with performance of other cognitive tests
How are theories supported?
Internal consistency of the measure (that is, within-measure)
Correlate with other behaviour measures
• Such as academic tests for verbal intelligence
How can theories be challenged?
Theory doesn’t fit with task data
Tasks are too narrow (lack ecological validity)
• Don’t capture enough aspects of the construct
Tasks are too broad
• Can be contaminated by other constructs
What did Binet make and why?
• Binet
o Goal- to develop techniques for identifying those children whose lack of success in normal classrooms suggested the need for some form of special education
o Only originally designed for children
o He devised a series of numerous reasoning tasks related to everyday problems of life but involving basic reasoning processes
o Learned skills like reading were not tested explicitly
Wanted to separate nature from education
o Kids of different ages can do different things
Age level assigned to each reasoning task
The youngest age at which a child of normal intelligence should be able to complete the task
Determined by the age at which a majority of “normal” children in the standardisation sample passed the task
Mental age- the age assigned to the most difficult task that you could complete
o Concerned to identify children whose mental age was below biological age
What were Binet’s stipulations?
o Scores are a practical device
Do not buttress any theory of intellect
Do not define anything innate
May not designate what they measure as “intelligence’ or other reified entity
o Scale is rough
It is an empirical guide to identifying mildly-retarded and learning disabled children
Not a device for ranking normal children
o Low scores shall not be used to mark children as innately incapable
Emphasis should be placed upon improvement through special training
What was Binet’s goal?
o Identification and education- the scale was devised only to identify students in need of remedial education ( help and improve)
o Intelligence in any meaningful sense of the word can be augmented by good education, it is not a fixed and inborn quantity
o Was an incremental theorist
What did Goddard do to the Binet test and what did he use it for?
o Goddard used Binet’s test to prevent immigration and propagation of “morons”
o Testing of new immigrants at Ellis island so that America wouldn’t be tainted
o By women trained in the detection of feeblemindness
o Thought people who couldn’t pass his test were degenerate and wouldn’t be allowed to migrate in
o Binet refused to define his scores as intelligence, Goddard regarded the scores as measures of a single, innate entity
Classification
• Idiot: mental age (<2)
• Imbecile: mental age (3-7)
• Feebleminded: mental age (8-12)
• Moron: Highest functioning mentally retarded
What did Terman do to the Binet test?
o Revised and published Binet’s test as the Standford-Binet
o Developed and publicised intelligence testing as measurement
o Became the standard against which other tests were validated
o Done with recruitment into army, jobs…
o Test became used in a way outside its original use
What is mental age and why is it problematic?
o Mental age- based on age level at which the majority of “normal” children in the standardisation sample passed the test
o Problematic- people may have same mental age but their intelligence likely to qualitatively be different
Difficult to make comparisons of intellectual performance across age levels
What is ratio IQ and what are its problems?
o Ratio IQ= (Mental Age/Chronological Age)*100
o Allows comparison of intellectual performance across age levels
o Ratio IQ only works if mental age increases proportionally with chronological age. Difficult to say anything substantive about adults
Intellectual ability plateaus at adulthood
Ratio IQ starts to break down at about 20.
What is deviation IQ?
o Way in which we can measure how far above/below the average performance for age group (in normative sample) you are placed in
How do you find deviation IQ?
- Do a test and see how your normative sample performs and look at frequencies
- Raw scores converted to Z distribution scores
- Raw score paced in context of normative group
- Calculate deviation IQ:
- IQ=100+z*15
What is the mean and SD of an IQ scale?
mean=100
SD=15
How do you calculate the Z score?
Z scores- have a mean of 0 and a standard deviation of 1
• To calculate Z score- Take raw score, subtract mean and put everything on standard deviation z= (X-M)/SD
Gives a measure of where along the distribution you fall
What are the advantages and disadvantages of IQ tests?
• Intelligence tests have high reliability and validity- often produce reproducible results and there is a correlation between achievement at school and high IQ, even if that correlation isn’t perfect
• However, there are so many aspects to intelligence that it cannot be described by a simple IQ number
• Does IQ measure what we culturally think intelligence is, or intelligence itself
o Different cultures have different ideas to what intelligence is
• A test appropriate in one setting wouldn’t be in another
What is the structure of the stanford-binet test (4th edition)?
-15 subtests in 4 areas of cognitive ability
-Gives Standard Age score, mean=100 and SD=16
-Verbal reasoning
–Vocab
–Comprehension
–Absurdities
–Verbal relations
-Abstract/Visual
reasoning
–Pattern analysis
–Copying
–Matrices
–Paper folding and cutting
-Quantitative reasoning
–Quantitative
–Number series
–Equation building
-Short term memory
–Bead memory
–Memory for sentences, digits and objects
What are the standard materials for the Stanford-Binet (IV edition) test?
• Standard materials- o Four booklets of printed cards o Blocks o Form board o Beads o Large picture of a unisex multi-ethnic doll o Record booklet o Guide • Examiner highly trained: o Recommendations on seating o Precise wording o Mode of query
How are tests administered?
o Not only standardized tests but also clinical observation
o Will indicate features of an individual’s work methods, problem solving approach and other qualitative aspects such as attention, persistence and unusual approaches to solve problems
• Separate tests in increasing order of difficulty
• To avoid boredom, tests intermixed
• Testing time varies according to age of patient
o Testing time 30-90 minutes
• Special-purpose batteries available for certain populations (e.g. blind, deaf…)
o But tests normed to those populations
• Guidelines for translators etc. also provided
General test process-
• Establish a basal and ceiling level for each task
o Basal level= four items passed in a row
o Ceiling level= three or more out of four items on a consecutive level are failed indicates testing to be discontinued
• Scoring
o Each item response is recorded verbatim
o Items are either passed or failed according to strict guildelines
o Five “free reponse” tests which must be handled carefully
• Raw score-
o Item number of highest test administered minus total number of attempted items failed
o This score is later converted to a scaled score
What is the Stanford Binet’s fifth edition classification?
145-160: very gifted 130-144: gifted 120-129: superior 110-119: high average 90-109: average 80-89: low average 70-79: bordeline impaired 55-69: mildly impaired 40-54: moderately impaired
What is the multifactor view of intelligence?
Thorndike
• There is something common underlying all tests- positive manifold
o Mental abilities always positively correlate
-Intelligence is a combination of multiple factors such as abstract thinking and concrete intelligence
What is the single factor view of intelligence?
Spearman’s general factor
Overarching general intelligence that underlies performance in all tests actor
• General intelligence- A mental attribute that is hypothesised as contributing to the performance of virtually any intellectual task
o Explains why scores on all subsets are related
Because all the subsets rely on g, and so all reflect whether the person has a lot of g or a little
o Explains why the correlations aren’t perfect
Because performance on each subtest also depends on specialized abilities
• Can think of intelligence having a hierarchical structure
• Data confirms this view
• If tasks from two different categories are chosen, then should expect to find a lower correlation than if the tasks are from two same categories, but should find a correlation nonetheless
What is Thurstone’s primary mental abilities view?
• Primary mental abilities independent of each other and manifest in different ways
What is the correlated factors theory on intelligence?
- A combination of Spearman’s general factor and Thurstone’s primary mental abilities
- Hierarchical notion of hierarchy of primary abilities overseen by general intelligence that people have
Who theorized fluid and crystallized intelligence?
Cattell
What is fluid intelligence?
The ability to grasp relations between things; deal with novelty
Nonverbal abilities, inductive and deductive reasoning
Culture-free in theory and independent of education
Ability to deal with stuff in an efficient way
Innate intelligence
What is crystallized intelligence?
Acquired knowledge and skills
Acculturated knowledge, requires exposure to culture, formal/informal education
May require some investment of fluid intelligence
Are both crystallized and fluid intelligence needed?
Yes
What are the primary mental abilities used to measure general fluid intelligence?
o Induction o Sequential reasoning o Quantitative reasoning o Temporal tracking o Figural reasoning
What are the primary mental abilities used to measure general crystallized intelligence?
o Verbal comprehension o Cognition of semantic relations o General information o Reading comprehension o Spelling ability o Verbal closure o Phonetic coding o Foreign language aptitude
Are Gf and Gc corelated? What are their trends?
• Although conceptually different, Gf and Gc correlate to varying extents
• Construct validation of Gf-Gc theory
o Show different developmental trends
o Fluid rises to young adulthood, then falls off in old age
o Crystallised rises and plateaus
o In childhood, Gf and Gc are strong because increase at same rate
o In later life, Gf and Gc are a lot weaker
• Someone with a high level of fluid intelligence is likely to be a fast learner and hence will easily acquire crystallised intelligence
What determines a good psychological assessment and what assumptions can be made?
o Ultimately, good psychological assessment depends on
o How well we can measure the ability or trait of interest, and
o How the answer is used
o Core assumption o Psychologists who use tests to measure psychological traits or states assume that: Such traits or states exist They can be quantified, and They can be measured
What is the classical test/true score theory?
an observed score has only two components. The True score and an error component
How can error be classified?
o Test construction Content of the test o Test administration Variability in examiner o Errors in scoring Failure to use rubric consistently o Interpretation subjectivity Evaluation of response
What is the formula for observed score and what does each ter mean?
• X=T+E • X- observed score o The actual measurement o Consists of true score and error • T- True score o Is the ideal measurement o What we strive for o Is constant for an individual o The average of a sample of observations will approximate the true score o If we can repeat measurement indefinitely, the long term mean (also called expectation) will be the true score o Systematic variation • Error- o Errors in measurement o Is random o Unrelated to the true score o Cannot be eliminated completely o Unsystematic variation
What is one drawback of the classical test theory?
The classic test theory does not distinguish between true variance and systematic error variance
That is, systematic error will not decrease the estimated reliability because it is not random
What is reliability?
Reliability is the ratio of true score variance to observed score variance
How do we estimate reliability?
- Test-Retest reliability
- Equivalent forms reliability
- Cronbach’s alpha
What is test-retest reliability?
Same group of people are measured twice on same test
• The reliability of a test can be estimated as the correlation between repeated administrations of the same test
• But a high correlation could be due to the stability of the measurement process over time (not necessarily precision in the measurement of the true score)
o May be a stable but not an accurate representation of the true score
• Can’t differentiate reliability from stability- be careful
What are the assumptions and problems in test-retest reliability
• Our assumption:
o When individuals are measured repeatedly, their true score remains the same
o BUT THERE COULD BE:
Change in true score amount
• Maturation
o Spelling ability might improve over time
• Reactivity
o Experience of taking the test might change true score
o First administration acts as a catalyst for change between administrations
• If change is not systematic, result in low test-retest reliability
Change in what is being measured-true score type
• The change is associated with a change in speed-accuracy trade-off
• Priorities might be different
Carry-over effects
• Remember original responses
• Inflates stability- so tend to get an over-estimate of reliability
What is equivalent forms reliability?
Measure the same phenomenon using two different forms of the test
Correlation between form 1 and form 2 is the reliability of each test
Reflects:
• Reliability
• The extent to which two forms measure the same thing
Not easy to come up with parallel tests of same difficulty
What is Cronbach’s alpha reliability?
Split-half reliability is an internal consistency estimate of reliability (correlation between halves)
But how do we split the test?
• People can split the test into many different tasks
If every possible split-half correlation was computed, the average would be Cronbach’s alpha
Cronbach’s alpha considers the relationship between items of the same test, the extent to which all items measure the same thing
Good reliable internally consistent test
What is validity?
Is the test appropriate for measuring the construct
What effect does systematic error have on validity?
A negative effect
What is measurement validity?
o The extent to which a test measures what it purports to measure
o Meaningfulness of scores
What is validity of decision?
o Is the test being used in the manner it was intended to be used
o The interpretation of scores needs to be valid
What are different aspects of validity?
- Content
- Construct
- Criterion
What does the content aspect of validity involve?
Content- are the items on the test good for testing that particular domain of behaviour
• Coverage of the domain
o Does the test assess behaviour that is representative of the domain of behaviour that we want to measure
o Define boundary and structure of the domain
o Boundary- what is considered part of the domain and what is not
o Structure- test content reflects the structure of the domain
What is involved in the construct aspect of validity?
Construct- have you defined constructs in a good way to develop a test to measure it
• Construct validity concerns the nature of the abilities (latent variables) captured by a test
• Evaluated by examining the relationship between scores on current test and other measures
o Convergent validity
Is the construct related to other theoretically similar constructs/tests?
Expect high correlation with similar constructs/tests
o Discriminant validity
Is the construct independent of other, unrelated, psychological constructs
• Expect low correlation with unrelated constructs
What is the criterion aspect of validity?
is it a good predictor of behaviour
What is a summary of how we measure intelligence?
- Work out what it is we want to measure (definitions- theoretical and pragmatic)
- Work out what it looks like (signs, manifest variables)
- Devise tests and scores
- Work out how it is structure (e.g. single factor vs multifactor)
- Assess whether our test is valid and reliable
What did Galton find as evidence that IQ is heritable?
• Sir Francis Galton- “Hereditary Genius” (1869)
o Analysis of genealogical trees of 145 eminent persons judges, politicians, scientists, poets, authors, artists, clerks
o Found that:
Prominent people have prominent relatives
The closer the kinship the more likely the relative is also prominent
o Hence, genius and feeble-mindedness runs in families
o Believed that can use artificial selection to increase intelligence among humans
What are some alternate explanations for Galton’s findings?
- However, findings can also be explained by the fact that offspring of families have better access to education
- Children of prominent people will be well educated and rich
- Related families have similar environment
- Difficult to disentangle effects of genetics vs environment
How could the relative roles of heredity and the environment be studied?
o Put rats that are genetically similar in different environments
o Put rats that are different in similar environments
o Family resemblance studies
• Hence, assess the role played by genetics and environment for a particular trait by
o Combining information from these two types of studies and/or
o Comparing correlations between degree of family resemblance and adoption studies
o Genetics and the environment cannot be studied separately
What are the assumptions on the studies of relative roles of heredity and the environment?
• If a psychological trait is affected by genetic factors, individuals that are more similar genetically should be more similar with respect to that trait
What are the problems on the studies of relative roles of heredity and the environment?
Problems
• Genetic relatedness is usually closely linked to environmental similarity
• Families tend to live together or near each other similar environments
What is the best that studies on the relative roles of heredity and the environment can give us?
- Family resemblance studies provide us with information about upper limit
- They give us combined effects of genetic and environmental influences
- Not great at disentangling genes and environment
Why are adoption studies useful in determining the factors influencing intelligence?
Genetically unrelated people are raised in the same environment
Similarity can be attributed to shared environment
Why are twin studies useful in determining the factors influencing intelligence?
Genetically similar people raised in different environments
Similarity can be more likely attributed to genetic factors
However; o Have a degree of shared environment Socio-economic status Family climate Nutrition o Have a degree of non-shared environment Pregnancy Siblings order Parental preference Peers, school Illnesses
What did Bouchard and McGue do and find?
• Summarised number of studies that looked at issue of concordance of intelligence between people that have different degrees of environment and genetic similarities
• Found correlations relating to shared environments on measurements of intelligence
• Found that correlations increase as degree of relatedness increases- suggests genetics
o Identical twins’ correlation in IQ was .86 when not separated at birth, but when separated at birth was .75
• Influence of environment makes data stray from theoretical value
• Evidence both for genetic and environmental influence in IQ scores
What is a heritability index?
the proportion of the total variation in a given characteristic in a given population that can be attributed to genetic differences between members of that population
Involves the comparison of two numbers:
- What is the total phenotypic variability
- How much of this variability can be understood in genetic terms
Are measures of heritability applicable to single individuals?
• Variation not attributable to genetic differences is caused by differences in the environment experienced by the members of the specified population
o Makes no sense to apply measures of heritability to single individuals, and it would be a mistake to read a heritability estimate as implying that a certain percentage of a person’s IQ came from her genes and the remainder from her environment
How can you calculate heritability measures?
• Heritability is simply the proportion of phenotypic variance (Pv) that is due to genetic influences (Gv)
o H= Gv/Pv
What numbers is the value of H between?
Always between 0 and 1
What does 1-H represent?
o Whatever remains of the obtained heritability reflects that part of phenotypic variance that is attributable to environmental and residual effects
o Thus, 1-H represents the combined effects of environmental and residual factors
What is the heritability for IQ in most environments?
Between 0.4 and 0.7
What can H be derived from?
o Dizygotic twins ( or other siblings) reared apart
These individuals share one-half of genetic variance (on average)
There is 100% environmental variance (different environments)
o Careful consideration of genetic and environmental similarity for different types of subjects allow for the use of other correlations as estimates of heritability
What are the assumptions of heritability?
o The heritability of a particular trait is not absolute- it is statistic for a given population at a given time
o Depends on
The genetic variability of that population
The degree of variation in its environment
o If we change these things the estimated heritability changes
o Calculating H assumes that genetic and environmental contribution are independent
What are the problems with heritability assumptions?
o Genotype-environment correlations and interaction
Genetic predispositions may lead to certain environments which encourage that genetic predisposition
Cannot conclude that the environment is independent of genes
o Tendency for assortative mating
Assumption that parental genetic correlation is zero
• Spousal correlations are .2 to .3, that is, people tend to mate with people who are similar to themselves
• If people mate with others who have similar levels of intelligence, they are also likely to have similar genotype relevant to intelligence
• Increases genetic effects in the population with each successive generation
• Tends to increase genetic similarity between parents and children- often not taken into consideration when calculations are done
o Heritability seems to vary with socio-economic status
High socio economic status- monozygotic twins correlations are higher than dizygotic correlations
• Opportunity for genetic differences to express themselves due to rich environment with higher amount of opportunities
Low socio economic status- monozygotic twins correlations are similar to dizygotic twins correlations
• Impoverished environment less opportunities genetic differences cannot be expressed or seen
Hence, in some settings, genes play a large role; in other settings, they do not
o Age of comparison
Correlations change from childhood to adulthood as experiences lead to increased realisation of similar genetic potential
• When child is young, lower correlations than when calculated at adulthood
• More opportunities to realise potential when older than younger
So H could change depending on the age at which it is estimated
o Selective placement of adoption
Children tend to be adopted out to higher SES, higher intelligence, motivated…
• So not a lot of data for adoptive parents in crappy environments
It is not random assignment- could restrict range and lower correlations between adoptive parents and children- inflates heritability estimates
What conclusions can we make from heritability?
If a trait has high heritability it means that it is not greatly affected by existing environmental differences experienced in that population
High heritability says nothing about the consequences of new environmental manipulations
• Getting glasses gets rid of genetic contributions to eyesight- environment has changed
o H is a population statistic
It tells us about average probabilities but it does not say anything about individual cases
o H is based on the assumption that we can distinguish between
Observed data (phenotype)
Latent causes which can be genetic and environmental
In practise, this is almost impossible
Why would researchers use identical twins to determine the heritability of mental abilities?
• H is best estimated by the correlation between MZ twins reared apart
o Gv is constant in monozygotic twins
o Environment is assumed to be maximally different, because they are apart
Any differences are attributed to environment
What are potential confounding factors that influence the interpretability of twin studies?
• Source of variability in twin studies
o Variations of shared genes
o Shared environment (reared together)
o Non-shared environments (reared apart; or reared together, but other environmental factors)
• This makes correlation not perfect
o Differences in IQ would be attributed to non-shared environment in monozygotic twins
o Differences in IQ would be attributed to gene variation in dizygotic twins
• Comparisons between monozygotic and dizygotic twins reared together
o They have maximally similar environments but differ with respect to degree of genetic similarity
o If a trait is influenced ONLY by the environment, the correlation between dizygotic twins should be the same as the correlation between monozygotic twins
o If heredity is important, MZ twins will be more similar than DZ twins
What is the IQ difference in males and females, as well as field differences? Why is this so?
• Females perform better than males at verbal abilities tests
• Males perform better than females at visual/spatial abilities tests
• There doesn’t seem to be a gender difference in IQ measures
• Are there biological differences between males or females, or is it cultural/exposure difference?
o The general trend is a decline in gender differences over the past fifty years
Evidence for environmental explanations of these differences
Is IQ variation larger within each group or between groups?
• Variation within each group is much larger than any between-group variations
What is the difference in measured IQ between white and black americans
• About 1 standard deviation of IQ points between white and black americans, with black americans having a lesser IQ
In decreasing order of IQ, what is the order of asian americans, black americans and white americans? Could these differences be environmental?
Asian, white, black
Yes
Outline the propositions put forward in the Bell curve
• Herrnstein and Murray- “the bell curve” book
o Argue that racial differences on IQ tests are inherent
Suggested this follows from substantial heritability of intelligence
Claimed that even after accounting for environment, there is still a 10 point difference between white and black americans
o Argued that this should be taken into account in school and social policy
Proposed eliminating welfare policies that encourage poor women to have babies
Suggest that waste money on education for black people because they are inherently less intelligent
o Society has been “dumbed down” as they take on people with lower intelligence- should try to weed them out
o Devoting resources to help the underprivileged means gifted students have not been able to reach their potential
o Resources should be shifted from supporting disadvantaged programs to programs that support high intelligence
What are issues with the bell curves arguments?
• There has to be a meaningful single number that can be given to intelligence
o But intelligence tests cover a range of different abilities
o Are results from different tests the same- single number from different tests means different things
• You have to be able to rank people in a single linear fashion and this rank needs to predict social outcomes
o Different people have different structures of intelligence- strengths and weaknesses
o Two individuals could have same IQ but could have different skill sets
• IQ has to be highly heritable
o At best, this holds within a population
o Estimates hold within a population but not necessarily in comparing different groups
• IQ has to be effectively unchangeable
o Flynn effect and stereotype threat
o Even if genetically determined, can be changed with environment
What did Helms find?
Negative correlation between identification with black culture and achievement
What did Steinberg find?
• Steinberg (1996) examined attitudes of Phidadelphia adolescents towards school
o Dominant attitudes of white per group was that conspicuous effort was frowned on, but so was poor achievement
Wanted to do well without trying
o African-Americans claimed high achievement was valuable, but were not threatened by poor achievement, so studying was not too important
o Asian-Americans (particularly immigrants) believed in the importance of high achievement but expected that it required sustained effort
What study was done on the stereotype threat?
o Steele and Aronson (1995) gave IQ type test to white and black US Stanford University student
o Told:
Test was diagnostic of intellectual ability
Laboratory tool for studying problem solving
o Race differences only when told diagnostic of intellectual ability
But test was exactly the same
Feeds into stereotype that blacks are not as good in intelligence tests as white, so underperformed in the test
What was Dar-Nimrod and Heine’s study?
Told students that maths tests differences are due to biological differences between genders
• Big difference between male and female participant performance
Told students that maths tests differences between genders are due to environmental differences
• Little difference between male and female participant performance
What is the Flynn effect?
There has been an increase in intelligence (raw scores of IQ test) over the last few decades
• Flynn (1987) showed increases of 5 to 25 points in a generation over 14 countries
-Changes were in fluid intelligence, not crystallised
Why is the Flynn effect occuring?
Evolution/genetic selection not possible as only take 1-2 generations to improve IQ
• Cannot be explained genetically
Environment- more likely explanation, but none of these explanations seem to capture such a rapid change
• Could be due to improved schooling
o But most changes in tests of fluid intelligence, not crystallised intelligence
• Could be better nutrition
o But poorer people had the biggest gains in nutrition, yet don’t show the biggest effects
• Could it be familiarity with tests
o Possible but most people not so familiar
• Could be changes in child-rearing
o Possible- parents pay more attention to kids
Go to early tutoring…
Flynn (2007) suggested that through modernization, a much larger proportion of people have become accustomed to dealing with abstract concepts and think of a different way
What can tests of cognitive function be used for?
o Identify areas of difficulty
And what sorts of things they’re good at to get around their deficits
o Help localise brain damage
Either neuropsychology assessments (in older days) or brain-scan but sometimes there might be deficits that show up on testing that don’t show up on brain scans
o Help devise rehabilitation strategies
o Assess competency/ medico-legal context
If they can return to work
Medico-legal context- courts will ask neuropsychological tests to see how much the person can be reimbursed
o Chart recovery of function/ effect of intervention
Assess rehabilitations programs to see if they work
o Chart decline (e.g. in dementia)
Need to demonstrate people are getting worse to see if its progressive disorder
o Assess the need for special education in children
Just like Binet originally intended
What are different cognitive domains you can test
- Memory
- Language
- Visuo-perceptual skills
- Praxis
- Attention
- Executive functions
What kinds of tests can you do to test cognitive domains?
• Picture completion
o Have to work out what’s missing from the picture
o Visual analysis
o Abstract thought
• Block design
o Visual analysis
o Spatial thinking
• Object comparison
o Patients give concrete answer
o Look for abstract answers- which is good
• Trail making test
o Have to connect dots in order of letters
Measures visual scanning and psychomotor speed
Can pick up attentional neglect
Test of speed
o Also can connect letters to their respective numbers
Measures ability to switch between competing trains of thought
• Copying complex drawings
o Planning
Jump from one thing to another or going through it in a systematic way
o Assess visuo-spatial skills and planning
• Stroop test
o Name the colour of the ink
o Words are colours and are inked in a different colour than their name suggests
o Assess ablity to inhibit an automatic response (i.e. cognitive control)
• Symbol-digit coding
o Symbols associated with different digits
o Given rows of numbers and have to put in symbols that can correspond to each number
o Assess psycho-motor speed
People with short term memory problems will be slower
• Vocabulary subset from WAIS or S-B, or National Adult Reading Test
o Tests word knowledge
o Can give estimate of pre-morbid intelligence
• Comprehension tests (general knowledge)
• Memory tests o Short term memory o Long-term memory (recall and recognition) Read a story and tell them to read it back o Visual vs verbal memory Stories, drawings • Specific language tests o Verbal comprehension and expression o Reading o Writing o Naming • Tests of visual recognition o Objects o Faces o Natural scenes • Test of praxis (skilled action) o Show me how you brush your teeth
What can occur due to traumatic brain injury?
• Traumatic brain injury
o Depends on where it is in the brain- widespread effects on brain tissue because:
Impacts injury to the brain as it hits the skull- bleeding and bruising
• Frontal and temporal lobes are vulnerable- often bears brunt of the impact
Rupture injury to the axons of neurons
• Communication between different regions of the brain becomes difficult
• Disconnection of different parts of the brain
o Slow speed of processing (due to white matter damage)
Digit substitution tests
o Memory difficulties ( due to damage to temporal lobes and to some extent, frontal lobe)
o Attention difficulties (often multi-factorial)
o Impaired executive function (due to damage to frontal lobes)
Poor planning
Difficulties with abstract thoughts
Difficulties switching mental set
Poor impulse control
Limited insight into their problems
o Often, well-established knowledge (concepts and facts) is well preserved
Fluid aspects of intelligence are damaged but crystallised is ok
What are strokes?
o Blockage of blood vessel due to clot neuronal tissue dies as a result of not having oxygen and blood flow
o Depends on where it is in the brain
What is alzheimer’s disease and what can occur due to it?
Progressive loss of brain tissue
Shrinking of brain
Severe atrophy which starts in the mesial temporal lobe (including hippocampus), then spreads to parietal lobes and dorsolateral prefrontal cortex
Presentation is after age 60
Memory impairment often the first presenting complaint and the most prominent
• On testing, there is both a failure to encode information and to store this information in a more permanent way
• Delayed recall is very poor and cueing doesn’t help retrieval
As disease advances, language, visuo-spatial, executive functions become compromised
General demeanour and personality usually preserved until late in the disease
• Differentiating factor between other neurodegenerative disorders
What is fronto-temporal dementia and what can occur due to it?
o Fronto-Temporal Dementia manifests as a progressive loss of language abilities and changes in personality and behaviour
Inability to speak fluently
Loss of knowledge of words and concepts
• Difficulty comprehending language
Poor impulse control, aggressiveness or apathy
Personality change
o Testing mental abilities can help in differential diagnosis
What is visual agnosias and what can occur due to it?
o Inability to recognise objects by sight
Could describe and copy it, but can’t link it to meaning
o Inability to recognise faces (prosopagnosia), not even their own
o Inability to judge the orientation of objects (orientation agnosia)
What is epilepsy and what might occur due to it?
o Seizures originate from temporal lobe/hippocampus so might have memory problems but it depends
What are common disorders in children?
- Specific learning impairments (dyslexia)
- Attention deficit hyperactivity disorder (ADHD)
- Autism spectrum disorder
