Mental Abilities Flashcards
Structure of mental abilities / Intelligence Biological, genetic, environmental bases of mental abilities Life outcomes Alternative ideas about intelligence Emotional intelligence
Personality
Differences among individuals in their typical style of behaving, thinking, and feeling across situations and across time
Mental Ability
Differences among people in their maximum performance in producing correct answers to various problems and questions
- “Intelligence”
Assessment of Mental Ability
Task difficulty due to demands on mental processes such as reasoning, understanding, imagining, and remembering
Not due to demands on physical skills or sensory abilities
Demand skills are roughly equally familiar to all persons
Mental Abilities: Overview
- The Structure
- Developmental Change and Stability
- Biological Bases
- Genetic and Environmental influences
- Life Outcomes
- Not all g-loaded tasks are the same
- Alternatives
- The Structure of Mental Ability
History of Intelligence
Galton (1822-1911)
Cattell (1860-1920)
Binet (1857-1911)
Spearman: invented the correlation coefficient and factor analysis
Thurstone’s primary factors
Galton (1822-1911)
First psychologist studying individual differences
Hereditary Genius: differences in intelligence are determined by genetic factors
Statistical and methodological approach
Didn’t measure mental abilities, but physical and sensory abilities, e.g., reaction time, sensory discrimination…
Cattell (1860-1920)
“Intelligence” = 10 basic psychological functions such as tactile discrimination, hearing, weight discrimination
Developed “mental” tests
Reliably measured individual differences in performance
Not mental abilities
Binet (1857-1911)
Set the foundations of modern intelligence testing
Developed a variety of tasks to measure mental abilities to identify children with lower relative to higher mental abilities
Pragmatic approach first intelligence test
Didn’t investigate the nature of mental abilities
Spearman’s g factor (1863-1945)
Conducted factor analysis and data-reduction procedures to show that different ability tests were significantly correlated
The common variance = a single, general factor g
First, Spearman showed that school grades in various courses were positively correlated with each other
Motivation or g factor of intelligence?
Subsequent research showed that students’ scores on a variety of mental ability tasks were correlated with each other
Some tasks had strong g-loadings, whereas others had weaker g-loadings
Highly g-loaded tasks demanded reasoning processes
“The eduction of relations and correlates”
Thurstone’s primary factors
g factor does not explain the relations among various kinds of mental abilities
Intelligence should be conceptualized at the ‘primary’ level
7 primary abilities
- Verbal fluency
- Verbal Comprehension
- Numerical Facility
- Spatial Visualization
- Memory
- Perceptual Speed
- Reasoning
g plus group factors
Combining Spearman’s and Thurstone’s theories into a hierarchical model
Hierarchical models:
Carroll’s (1993) three stratum theory
Cattell-Horn-Carroll (CHC) theory
Carroll’s (1993) three stratum theory
Narrow (I), broad (II), and general (III) levels differ in degree of generality
Broad (II): 69 narrow abilities, basic constitutional and long standing characteristics that govern or influence a great variety of behaviours in a given domain
Cattell-Horn-Carroll (CHC) theory
Narrow (I), broad (II), and general (III) levels differ in degree of generality
Different factors in the II level
2.1 Developmental changes in mean levels of intelligence
Absolute levels of g:
- Rapid increase during childhood
- Continue to increase into late adolescence
- Decrease during old age
What happens in between early and late life stages?
Differences between subtests:
Wisdom, Mignogna, & Collins, 2012
Verbal ability somewhat higher for 40s-60s
Spatial ability & perceptual speed highest for young adults
Possible “cohort” effects
Lack of longitudinal research
2.2. Stability of intelligence across the life span
Rank order stability = Individual differences in mental abilities stable across the life span despite mean level changes (maintenance of individual position within a group)
Relative levels of mental ability show high levels of stability
Deary, Whiteman, Starr, Whalley, and Fox (2004)
- Biological bases of mental ability
- Brain size
- Nerve conduction velocity
- Reaction Time
- Inspection Time
- Brain waves
- Brain glucose metabolism
3.1. Brain size
Modest positive correlation with external head size
Brain volume (measured with MRI scan) shows an average correlation of .33 with intelligence (McDaniel, 2005)
Some regions of the brain might be the crucial “intelligent” regions
3.2. Nerve conduction velocity 神經傳導速度
Speed of electrical impulses between cells of the brain and nervous system (~Galton)
Research findings to date are inconsistent
- Reaction Time
e. g., Jensen Reaction Time Box
Indication that speed of brain and nervous system is related to g
longer RT = lower intelligence
3.4. Inspection Time
Exposure duration required for a human subject to reliably identify a simple stimulus
Mental speed is related to g
High speed = high score
3.5. Brain waves
EEG: Measuring electrical brain activity with electrodes -> Brain waves
Higher IQ scores relate to greater overall complexity of the waves
3.6. Brain glucose metabolism
PET: injecting small amount of radioactive glucose to measure the amount of glucose being metabolized in the brain
Higher IQ scores = less glucose consumption during IQ tasks
-> Brain is more efficient
- Genetic and environmental influences on mental ability
- Genetic influence
- Womb environment
- Nutrition
- Birth order
4.1. Genetic influences
MZ twins sharing 100% of their genes vs. DZ twins sharing 50%
Twins or siblings raised together vs. apart (adoption)
Family context becomes less important as one grows up
“Behavioural genetics”
Twins and siblings as valuable source of information to estimate genetic effects and effects of shared and unique environment
4.2. Womb environment
The first environmental influence on traits and mental abilities is the influence of the womb environment, e.g. nutrients, toxins, hormones, …
MZ twins (shared womb environment) vs. non-twin siblings
Sibling pairs vs. parent-child pairs
Conclusion of Devlin et al. (1997)
Heritability of mental ability has been overestimated in twin studies
Effects of chorion type on mental ability (Jacobs et al. 2001)
2/3 of the MZ twins have the same chorion, 1/3 their own
-> Levels of hormones and nutrients may be different
4.3. Nutrition
Fetal alcohol poisoning, lead poisoning, severe malnutrition 營養不良 -> lower IQ