General Psychology (PY110)

General Psychology (PY110) Chapter 6 Thinking & Intelligence

Thinking • Thinking is the processing of information to solve problems and make judgments and decisions

A Problem • A situation in which there is a goal, but it is not clear how to reach the goal • A well-defined problem is one with clear specifications of the start state (where you are), goal state (where you want to be) and the processes for reaching the goal state (how to get there) • An ill-defined problem is a problem lacking clear specification of the start state, goal state, or the processes for reaching the goal state

Problem Solving Involves two steps... Interpreting the problem Trying to solvethe problem

Blocks to Problem Solving Interpretation blocks • Fixation is the inability to create a new interpretation of a problem • For instance, in the 9-dot problem, the directions do not say one cannot go “outside” the mental square formed by the 9 dots

Blocks to Problem Solving Interpretation blocks • Functional fixedness is the inability to see that an object can have a function other than its typical one • For example, if you need a screwdriver but don’t have one, a dime could be used to serve the purpose of a screwdriver • Occurs during the definition phase of problem solving • Limits our ability to solve problems that require using an object in a novel way • To combat functional fixedness, you should systematically think about the possible novel uses of all the various objects in the problem environment

Blocks to Problem Solving Strategy blocks • Our past experience with problem solving can lead us to mental set, the tendency to use previously successful solution strategies without considering others that may be more appropriate for the current problem • When searching for new approaches to a problem, we may experience insight, a new way of interpreting a problem that gives you the solution

The Matchstick Problem Move just one matchstick to make the sum correct.

Overcoming Blocks • To combat the blocks in problems solving, ask yourself questions such as: • Is my interpretations of the problem unnecessarily constraining possible solutions? • Can I use any of the objects in the problem in novel ways to solve the problem? • Do I need a new type of solution strategy?

Solution Strategies Algorithm Heuristic

Algorithm • A step-by-step procedure that guarantees a correct answer to a problem • For example, using multiplication correctly guarantees you the correct solution to a multiplication problem • However, over reliance on algorithms can result in Functional Fixedness

Heuristic • ‘Rules of Thumb’ or shortcuts which may help solve a problem quickly • A solution strategy that seems reasonable given your past experiences with solving problems, especially similar problems • May pay off with a quick correct answer, but it may lead to no answer or an incorrect one

Hypothesis Testing ConfirmationBias BeliefPerseverance IllusoryCorrelation

Confirmation Bias • The tendency to seek evidence that agrees with one’s belief system • That is, people do not test their beliefs about the world by trying to disconfirm them, but rather, by trying to confirm them • In example, some believed that there is a link between race and IQ

Illusory Correlation • The erroneous belief that two variables are related when they actually are not • We tend to focus on instances in which there seems to be a relationship between the variables in question, ignoring all disconfirming instances • If we believe a relationship exists between two things (e.g., wearing a certain color shirt and getting a good grade on a test), then we will tend to notice and remember instances that confirm this relationship

Belief Perseverance • The tendency to cling to one’s beliefs in the face of contradictory evidence • Personal-who reasoning is questioning a well-established finding because you know a person (one instance) who violates the established finding • For example, a student may insist that eating a steak, baked potato loaded with butter, sour cream, cheese, and salt for dinner is healthy because his grandfather did so every night for 50 years and lived to be 90 years old

Binet & Simon • The fist accepted intelligence test was developed by Binet and Simon • It was developed a test to diagnose children who were subnormal and likely to experience problems is school • Based on the concept of mental age – the age typically associated with a child’s level of performance • If a child’s mental age was less than their chronological age, they would need remedial work • Demonstrates a nurture emphasis on intelligence

Lewis Terman • Revised Binet and Simon’s test at Stanford University for American school children • This became known as the Stanford-Binet test of intelligence, Terman used the classic intelligence quotient formula • IQ = (mental age/chronological age) X 100 • If a child’s mental age is greater than the child’s chronological age, the child’s IQ wasgreater than 100 • When a child’s mental age is less than thechild’s chronological age, the child’s IQ was less than 100

Weschler • David Wechsler was Chief Psychologist at Bellevue Hospital in New York City in the 1930s and had adult patients from diverse backgrounds • The Stanford-Binet was not designed to assess adult intelligence, and the IQ was particularly problematic for adults because at some point the mental age levels off but the chronological age keeps increasing (so a person’s IQ declines simply because of natural aging) • Developed his own tests, the Wechsler Bellevue Scale, in 1939 (later called the Wechsler Adult Intelligence Scale – WAIS) • Provides test scores for a battery of both verbal tests (such as vocabulary and comprehension) and performance (non-verbal) tests (such as block design and picture arrangement)

Deviation IQ Scores • To calculate a person’s deviation IQ, Wechsler compared how far the person’s raw score was from the mean raw score in terms of standard deviation units from the mean • To make the deviation scores resemble the IQ formula, he set the mean to 100 and the standard deviation to 15 • Deviation IQ score = 100 plus or minus (15x the number of standard deviation units a person’s raw test score is from the mean for the relevant age group norms)

Deviation IQ Scores on the WAIS

Psychometric Properties Standardization Reliability Validity

Standardization • Allows test scores to be interpreted by against norms • The test must be given to a large representative sample of the relevant population, and the scores of this sample serve as norms for interpretation • For example, Terman standardized his Stanford-Binet on American children of various ages – any child’s raw score could be compared to the standardization norms to calculate the child’s mental age • Wechsler collected standardization data for various adult age groups, and the data for each age group form a normal distribution

Reliability The extent to which the scores for a test are consistent • In the test-retest method, the test is given twice to the same sample, and the correlation coefficient for the two sets of scores is computed • A reliable test yields a strong positive correlation • Alternate form reliability can be assessed if multiple forms of the test are available • Here, a researcher gives different forms of the test to the same sample at different times and computes the correlation coefficient for performance on the two forms • Split-half reliability is determined by correlating performance of two halves of one given test • For example, the odd and even number items

Validity • The extent to which a test measures what it is supposed to measure or predict what it is supposed to predict • Content validity means that the test covers the content that it is supposed to cover • Predictive validity means that the test predicts behavior that is related to what is being measured by the test • It is important to note that if a test is valid, it will also be reliable • However, a test can be reliable, but not valid (e.g., using wrist size to measure intelligence; wrist size is quite reliable, but does not contain validity given the interest in measuring intelligence)

Theories of Intelligence • Cattell and Horn proposed two types of intelligence, which have been of interest to researchers in aging • Fluid intelligence refers to abstract reasoning, memory, and the speed of information processing • Crystallized intelligence refers to accumulated knowledge and verbal and numerical skills

Theories of Intelligence • Howard Gardner’s theory of multiple intelligences includes 8 independent types of intelligence

Theories of Intelligence • Robert Sternberg’striarchic theory of intelligence proposes three types of intelligence 1. Analytical intelligence is essentially what is measured by standard intelligence tests, the necessary skills for good academic performance 2. Practical intelligence could be equated with good common sense or “street smarts” 3. Creative intelligence is concerned with the ability to solve novel problems and deal with unusual situations

Nature vs. Nurture • Most contemporary psychologists believe that both heredity (nature) and environmental experiences (nurture) are important in determining intelligence • The disagreement is over the relative contribution of each part to intelligence

The Case for Nature • Genetic similarity studies are important in determining the relative contribution of nature and nurture to intelligence • Identical twins have 100% genetic similarity • Fraternal twins and siblings have 50% similarity • Two unrelated people have 0% similarity • If intelligence were due to heredity, the average correlations between intelligence scores should decrease as genetic similarity decreases, and researchers have found this to be the case

The Case for Nurture • However, there are also results that support environmental influences on intelligence • For example, if identical twins are raised together, the correlation between their intelligence test scores is +0.86, but if the identical twins are raised apart, the correlation falls to +0.72

Both Nature and Nurture • The average correlation between fraternal twins raised together (+0.60) is less than that for identical twins reared apart (+0.72), indicating the influence of heredity • The average correlation is greater than that for ordinary siblings reared together (+0.47), indicating environmental influences because the environment influences of fraternal twins is more similar than for ordinary siblings at different ages

The Case for Both Nature and Nurture • There is a modest correlation between the intelligence test scores of adopted children with their parents, and this correlation disappears as the children age • The correlation between the scores for adopted children and their biological parents, however, increases as the children age • This stronger relationship between a person’s intelligence and that of their biological parents means that nature plays a larger role in determining a person’s intelligence than environmental experiences

The Flynn Effect • Refers to the fact that in the United States and other Western industrialized nations, average intelligence scores have improved steadily over the past century • Proposed explanations involve many environmental factors such as better nutrition and more education

General Psychology (PY110)