Refers differences among people in their typical behavioral tendencies
--> the ways they generally act, think, feel in various situations
Variation in mental abilities
Refer to differences among people in their maximum performance in producing correct answers to various problems or questions
On what aspects do mental abilities researchers typically focus on ?
5. Reading comprehension
--> skills that are roughly equally familiar to all persons
James McKeen Cattell + Francis Galton are considered early researchers of mental abilities.
Which aspects did they focus on ?
Which approach did they use to come about the problem ?
They believed that differences in mental abilities stemmed from individual differences in physical or sensory abilities
--> they therefore tried to determine whether those abilities would discriminate between people who were said to differ in intelligence
Who was the first researcher to develop tasks assessing mental abilities ?
French psychologist Alfred Binet
--> developed a variety of tasks that were used to measure the mental ability of children
Is a british psychologist that studied under Wilhelm Wundt
--> he is considered to be the most important figure in the history of the science of mental abilities
Which approach did Spearman use to assess the differences in mental abilities ?
1. He calculated correlations among the grades in various courses (Factor analysis)
--> thought students grade were a good indicator of their mental ability
2. Then tested students directly in a variety of tasks
--> intended to asses different aspects of mental ability
What were Spearman's results ?
1. The results among various tasks tended to be substantially positively correlated with each other
2. Some of these tasks tended to show strong correlations with most other tasks (high g-loadings), whereas other tasks tended to show weaker correlations (low g-loadings)
What did Spearman conclude based on his findings ?
He concluded that performance on each task had to be influenced by a general mental ability
= "General Intelligence" (g)
High + Low g-loading tasks both involved the same kind of content, suggesting that the content didn't matter.
What made the difference in the high vs low g-loading tasks?
The mental processes that were required to solve them.
1. High g-loading tasks require some kind of reasoning
e.g.: "educing relations + correlates"
2. Low g-loading tasks involve simpler mental processes that are automatic or involve following rules
ex.: spelling words, calculation of numbers
What does "The principle of the indifference of the indicator" suggest ?
That the content of the task (indicator) is unimportant (indifferent) in determining whether the task will show a high or low g-loading
What was american psychologist Thurstone's criticism on Spearman ?
What did he discover ?
What were his conclusions ?
1. According to him a g-factor did not adequately explain the relations among various kinds of mental abilities
2. Discovered that tasks having similar content/ requiring similar mental processes would be highly correlated with each other
--> higher than expected based on g-loadings
3. He concluded that there were at least 7 important factors
--> g alone is not sufficient to explain the pattern of relations among different mental ability tasks
Which were the 7 primary Factors ? (Thurstone)
1. Verbal fluency
2. Verbal comprehension
3. Numerical facility
4. Spatial visualization
6. Perceptual speed
What are the developmental changes in the mean levels of mental ability ?
1. Levels of g increase during childhood into late adolescence, then decrease during old age
2. Young adults average the highest
Do individual differences in mental abilities remain stable over the course of a lifespan ?
Yes, they do
--> studies showed that individuals scoring the highest at a young age also scored the highest at older age
Which factors form a biological bases for individual differences in mental abilities ?
1. Brain size
2. Nerve conduction speed
a) reaction time
b) inspection time
c) brain waves
3. Brain glucose metabolism
Does a bigger brain size equal higher mental abilities ?
The overall size of the brain actually might be less important than the sizes of certain regions of the brain
--> not every brain region is involved in thinking
Can reaction or inspection times be associated with higher or lower scores on tests for mental abilities ?
they can as they are an indicator of the speed with which the brain + NS can operate
=> they therefore form the basis for the g-factor of mental ability
How is the rate at which the brain uses glucose, a good indicator of higher or lower mental abilities ?
How can this be measured ?
1. Individuals with higher levels of mental ability tend to have brains that consume less glucose while performing mental ability tasks
--> the brains are therefore more efficient, requiring less glucose
2. This can be measured by using a PET scan
How much are the levels of mental ability dependent/influenced by genetic factors ?
1. For young children this is equally attributable to their environment as to their genetic inheritances
2. As they grow up the differences become more strongly related to their genetic inheritances
What is the "Womb environment"?
How does it influence the level of mental ability ?
1. The womb environment is features the nutrients, toxins + hormones to which the developing fetus is exposed
2. It is possible that some port if the genetic influence is rather due to the womb environment
To what extent does IQ correlate with the birth order ? If so, where do the differences stem from ?
First born children have slightly higher IQs than do their siblings who were second and so on
--> this is due to a better social environment that first borns encounter
e.g.: get more attention
Why did the heritable differences in mental ability persist across the generations ?
Mutations will disrupt brain functioning + will tend to become less frequent across generations due to natural selection
--> BUT: new mutations will arise with each generation
Conclusion: If people differ in the number of mutations they carry, then this will make them differ in mental ability
To what extent does IQ correlate with Job performance, occupational status and income ?
1. Workers with high levels of mental ability will likely be better able to solve problems
--> higher level of job performance
2. Depends on the nature of the job + level of social mobility in society
Why is it that IQ + longevity correlate ?
1. Lower IQ will indicate not well functioning brain + body and health related problems
2. Attributable to the relation of IQ with behaviors that influence health
People who have lower IQs are more likely to commit a crime.
Why is that ?
They may become frustrated by their poorer prospects for achieving success
--> people with higher IQs will more likely recognize the risks coming with committing a crime
What is a "Novel task" ?
Novel tasks are indicators of fluid ability
--> requires a flexible response to a new situation
--> related to High g-loadings
What is a "Familiar task" ?
Indicators of crystallized ability
--> requires the use of some well learned skills/knowledge
--> related to low g-loadings
Are people getting smarter ?
1. No, because the increases are not general to all mental abilities
2. Yes because we're able to solve more unusual problems
Garners theory of multiple intelligences
1. States that there are 8 distinct kinds of intelligence, saying that everyone has his own strengths + weaknesses
2. Evidence that there are people who are strong in several abilities at the same time
--> implication of a general mental ability (constraint)