Human Mental Abilities Flashcards
What are mental abilities?
Mental abilities: the capacity to perform the higher mental processes of reasoning, remembering, understanding and problem solving - sometimes subsumed under the term ‘intelligence’
We study the way they vary across individuals NOT what is common.
What is a construct?
A construct is a theoretical entity that often cannot be measured directly, but can be assessed using a number of indicators or manifest variables.
Intelligence is considered a construct but is something that we can infer from observing behaviour.
How might we measure a construct such as intelligence?
Step 1: define it i.e. what is intelligence?
‘Intelligence is a word with so many meanings that finally it has none’ - Charles Spearman (1927)
‘Intelligence is what intelligence tests test’ - Boring (1951) - problems as it is a very circular model
Step 2: operationalise it i.e. what does intelligent behaviour look like?
- Maybe even easier to ask what does unintelligent behaviour look like
- Need to devise a test to measure observable behaviour and operationalise the construct
Example: reaction time reflects ‘processing speed’ and number of items remembered reflects ‘working memory capacity.’
Theory and measurement are inextricably linked
You need a good theory in order to develop a good measure
But you also need a good test to accurately measure what you want to measure
What are latent and manifest variables?
A manifest variable is one that CAN be directly measured or observed. It is the opposite of a latent variable, which is a factor that cannot be directly observed, and needs a manifest variable assigned to it as an indicator to test whether or not it is present.
What are implicit theories of intelligence?
Informal definitions of intelligence, beliefs we all hold.
Blackwell, Trześniewski and Dweck (2007) looked at the learning trajectories of 7th graders.
- The belief that intelligence is malleable (incremental theory) predicted an upward trajectory in grades over the two years of high school, while a belief that intelligence is fixed (entity theory) predicted a flat trajectory
- Holding an incremental theory led to more effort and a more positive response to failure
Stenburg (1981) asked experts and general population what behaviours show good intelligence:
- Verbal intelligence: good vocabulary, converses easily on lots of subjects
- Problem solving: makes good decisions, poses problems in optimal way, plans ahead
- Practical intelligence: sizes up situation well, determines how to achieve goals, displays an interest in the world at large
What are explicit theories of intelligence?
Explicit theories use data collected from people performing tasks that require cognition.
Define the scope of the psychological construct they deal with
- Either whole domain (intelligence) or
- Specific subsets (e.g. verbal performance)
Theories are supported by (mostly indirect) evidence
- Internal consistency of the measure i.e. within-measure
- Correlate with other behaviour measures
Theory can be challenged because
- Doesn’t fit task data - theory is wrong and needs changing
- Measure is not good
- Tasks are too narrow, or lack ecological validity
- Tasks are too broad
No one theory can account for it all.
What is Binet’s scale?
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
e.g. if you were 5 years old and able to solve tasks that were appropriate for 7 but not above, you had a mental age of 7
What is Binet’s goal?
Identification and education - the scale was devised only to identify students in need of remedial education (i.e. to help and improve)
He believed intelligence can be augmented by good education; it is not a fixed and inborn quantity
What are Binet’s stipulations?
- The scores are a practical device
- They do not buttress any theory of intellect (theory came later)
- They do not define anything innate
- We may not designate what they measure as ‘intelligence’ or any other latent variable - The scale is rough
- It is an empirical guide to identifying mildly-retarded and learning disabled children
- It is not a device for ranking normal children - Low scores shall not be used to mark children as innately incapable
- Emphasis should be placed upon improvement through special training
Contributions of H.H Goddard to the Binet
Brought Binet’s Test to the USA
- He used the test to prevent immigration and propagation of ‘morons’
- Testing of new immigrants at Ellis Island - by women trained in the detection of feeblemindedness (degenerate beings, responsible for many, if not most social problems)
Although Binet refused to define his scores as intelligence, Goddard regarded the scores as measures of a single, innate entity.
Classification (not derogatory at the time)
Idiot: Mental Age >2
Imbecile: Mental Age 3-7
Feebleminded: Mental Age 8-12
Moron: highest functioning mentally retarded
Terman’s Contributions to Binet
- Revised and published Binet’s test as the Stanford-Binet
- Developed and published intelligence testing as “measurement”
- Became the standard against which others were validated
Even then there was a concern that people with low intelligence will be considered as congenitally and hopelessly inferior.
What is the Intelligence Quotient (IQ)?
Introduced in the Stanford-Binet test
Recall that mental age is based on the age level at which the majority of ‘normal’ children in the standardisation sample passed the test: this is problematic
What is ratio IQ?
Was the original measure used in Stanford-Binet (now uses deviation IQ)
ratio IQ = mental age/chronological age x 100
What are the problems with ratio IQ?
- Ratio IQ only works if mental age increases proportionally with chronological age and we know that’s not the case
- Difficult to make comparisons of intellectual performance across age levels e.g. who is smarter, a 13 yr old with a mental age of 15 or an 8 year old with a mental age of 10?
- Difficult to apply to adults
What would be an ‘age-level-typical’ task for a 43 year old
What does it mean if a 50 year old has a mental age of 25
What are deviation scores?
Deviation scores (tells you where you sit relative to others like you)
From this can start to work out where a particular score might sit in the distribution
You can also measure how far one of the scores deviates from the mean - z score
Example: if you score 8, then you have scored at or above 96% of the population. Or you are 3 SDs higher than the average of 5.
Why is it important to standardise?
Comparing Raw Scores across Groups - Possible normative groups (subgroups): 14 yr old school children (general population) 18 yr old university students 8 year old school children
A score may have different percentile ranking for each group, and thus different psychological interpretations.
That is why it’s important to standardise these scores.
Standardising (norming) a test uses the ‘normal distribution’:
Raw scores → Z-scores → Deviation IQ scores
What is deviation IQ?
IQ scores mean the same thing regardless of the comparison group
IQ=100 means you are average at any age (consistent with the ratio IQ familiar to psychologists)
All other scores reflect how far your score deviates from the average
- IQ of 70 means you are 2 SDs below the average
- IQ of 115 means you are 1 SD above the average
What is the set up for the Standford-Binet IV test?
- 15 subsets in Four areas of cognitive ability
- Multiple separate tests, each in order of difficulty for 30-90 mins
- Special-purpose batteries available for certain populations e.g. blind, motor impaired, deaf etc
Standard materials: Four booklets of printed cards, blocks, form board, beads, large picture of a unisex, multi-ethnic doll, record booklet, guide
Examiner highly trained: recommendations on seating, precise wording, mode of query
Clinicians: not only standardized tests but also clinical observation. Will indicate features of an individual’s work methods, problem solving approach, and other qualitative aspects
What is the general test process of the Stanford-Binet IV?
Establish a basal and ceiling level for each task - usually suggested by examinee’s age
- Basal level = four items passed in a row
- Ceiling level = three or more out of four consecutive items are failed (discontinue)
Scoring
- Each item response is recorded verbatim
- Items are either passed or failed according to strict guidelines
Raw score = Number of correctly answered items
- This score is later converted to a scaled score
Gives Standard Age Score (SAS), mean = 100, SD = 16
What is group testing?
- Raven’s Progressive Matrices?
- Prototypical test of fluid intelligence (Gf)
- Broad ability concerned with basic processes that depends only minimally on learning and acculturation
Distinguish between a single underlying factor and multiple abilities
Single Factor: All of the tests load on one intelligence factor (g)
Uncorrelated factors: a range of primary mental abilities that are unrelated to each other
Or you could have both:
Have factors that are relatively independent of each other but may be correlated through general factor (g)
- We try to infer by seeing how the individual scores correlate
- If they rise and fall together (are correlated) this suggests they are linked - different tests may depend on single ability
- If rise and fall independently (not correlated) this suggests they are not linked - different tests may depend on different abilities
What are the different types of correlation?
Positive: as scores on one variable increase, scores on the other variable also tend to increase
Negative: as scores on one variable increase, scores on the other variable tend to decrease
Zero: no systematic relationship between scores on the two variables
Spearman’s observations on how test scores correlated with each other?
Observation 1: all mental abilities correlate with each other to some extent
- There is something common underlying all the tests - positive manifold
- Some researchers interpret these results as meaning there is a General intelligence factor reflected - Spearman’s g
Observation 2: there seem to be multiple clusters of stronger correlation that are only weakly related to each other
- Whatever factor is ‘causing’ the correlations between tests 1-3, is different to the factor that is ‘causing’ the correlations between tests 4-6
Conclusions
- There is something common underlying all the tests - positive manifold
- There are separate factors underlying performance on tests 1-3 vs 4-6
What is fluid and crystallized intelligence?
General Fluid Intelligence (Gf)
- The ability to grasp relations between things; solve novel reasoning problems
- Non-verbal abilities, inductive and deductive reasoning
General Crystallized Intelligence (Gc)
- Using acquired knowledge and skills
- Requires exposure to culture, formal/informal education
- May require some investment of fluid intelligence
Performance on a single task can (and is likely to) require both.
