Chapter 11 pt. 2: Intelligence Assessment

Warm Up Pick up warm up off of the overhead Pick up warm up off of the overhead Work Alone Work Alone 15 minutes 15 minutes

Assessing Intelligence: Aptitude vs. Achievement Test Aptitude Tests: are tests designed to predict a person’s future performance. Aptitude Tests: are tests designed to predict a person’s future performance. SAT’s and GRE’s SAT’s and GRE’s Achievement Test: a test designed to assess what a person has learned. Achievement Test: a test designed to assess what a person has learned. Midterm Psych exam, chapter 3 history test, etc. Midterm Psych exam, chapter 3 history test, etc.

Assessing Intelligence Wechsler Adult Intelligence Scale (WAIS) Wechsler Adult Intelligence Scale (WAIS) most widely used intelligence test most widely used intelligence test subtests subtests verbal verbal performance (nonverbal) performance (nonverbal) Also a WISC (Wechsler Intelligence Test for Children). Also a WISC (Wechsler Intelligence Test for Children).

Assessing Intelligence- Sample Items from the WAIS VERBAL General Information Similarities Arithmetic Reasoning Vocabulary Comprehension Digit Span PERFORMANCE Picture Completion Picture Arrangement Block Design Object Assembly Digit-Symbol Substitution

WAIS SAMPLE

Qualities of A Good Test To be accepted all psychological tests must be: To be accepted all psychological tests must be: 1. Standardized 2. Reliable 3. Valid

Standardization Standardization: defining meaningful scores by comparison with the performance of a pretested group. Standardization: defining meaningful scores by comparison with the performance of a pretested group. Your scores are compared with the pretested group who took the test. Your scores are compared with the pretested group who took the test. Standardized tests usually follow a normal distribution. Standardized tests usually follow a normal distribution. Normal Distribution: bell shaped curve that describes the distribution of many physical and psychological properties. Most scores fall near average, and fewer and fewer scores lie near the extreme. Normal Distribution: bell shaped curve that describes the distribution of many physical and psychological properties. Most scores fall near average, and fewer and fewer scores lie near the extreme.

The Normal Curve (Know My Distributions) Ninety-five percent of all people fall within 30 points of 100 Number of scores Wechsler intelligence score Sixty-eight percent of people score within 15 points above or below 100

Reliability vs. Validity (DON’T MIX THEM UP) Reliability deals with consistency. assessed by consistency of scores on: Reliability deals with consistency. assessed by consistency of scores on: two halves of the test two halves of the test alternate forms of the test alternate forms of the test retesting the same individual retesting the same individual Weschler and Standford Binet test +.9 Weschler and Standford Binet test +.9 Validity deals with predictability. Does the test measure what it is supposed to measure? Validity deals with predictability. Does the test measure what it is supposed to measure?

Types of Validity Content Validity: the extent to which a test samples the behavior that is of interest.Would a maneuverability test on a skateboard have content validity for testing to see if your qualified to drive? Content Validity: the extent to which a test samples the behavior that is of interest.Would a maneuverability test on a skateboard have content validity for testing to see if your qualified to drive? Predictive Validity: The success with which a test predicts the behavior it is supposed to predict. Predictive Validity: The success with which a test predicts the behavior it is supposed to predict. Do high SAT scores correlate with high college grades? Do high SAT scores correlate with high college grades?

Predictive Validity is Based on Criterion Criterion: the behavior that a test is supposed to predict. Is used to see if test is successful. Criterion: the behavior that a test is supposed to predict. Is used to see if test is successful. What would the criterion be for the GRE’s? What would the criterion be for the GRE’s?

The Flynn Effect Since the advent of intelligence tests, people’s IQ scores have been improving with time (flynn effect). Since the advent of intelligence tests, people’s IQ scores have been improving with time (flynn effect). If standardized with today’s tests, scores 80 years ago would have a average IQ of 76. If standardized with today’s tests, scores 80 years ago would have a average IQ of 76. Possible Causes? Possible Causes?

The Flynn Effect

Stability of Change? Can infant tests predict future intelligence? Can infant tests predict future intelligence? Picture Test Picture Test Starting at Age 4 may predict future IQ Starting at Age 4 may predict future IQ Age 7 scores become stable,but not fixed Age 7 scores become stable,but not fixed

Low Extreme of Intelligence Mental Retardation: condition of limited mental ability, indicated by an intelligence score of below 70 and difficulty adapting to the demands of life. Mental Retardation: condition of limited mental ability, indicated by an intelligence score of below 70 and difficulty adapting to the demands of life.

Low Extreme of Intelligence Down Syndrome: condition of retardation and associated physical disorders caused by an extra chromosome in one’s genetic makeup. Down Syndrome: condition of retardation and associated physical disorders caused by an extra chromosome in one’s genetic makeup. Many mentally retarded people with Down Syndrome can adapt to disorder and some have earned college degrees with accomdations…nearly all learn how to read. Many mentally retarded people with Down Syndrome can adapt to disorder and some have earned college degrees with accomdations…nearly all learn how to read.

Degrees of Mental Retardation Level Typical Intelligence Scores Percentage of the Retarded Adaptation to Demands of Life Mild % Most learn academic skills up to sixth-grade level. Adults may, with assistance, achieve self-supporting social and vocational skills. Moderate May progress to second-grade level. academically. Adults may contribute to their own support by labor in sheltered workshops. Severe May learn to talk and perform simple work tasks under close supervision but are generally unable to profit from vocational training.

Gifted Smart kids are usually not “weird” Smart kids are usually not “weird” Tend to get higher degrees Tend to get higher degrees Should gifted children be “tracked” in school? Should gifted children be “tracked” in school?

Is Intelligence Genetic or Environmental? Influenced by both, but the most genetically similar have the most similar scores. Similarity of intelligence scores (correlation) Identical twins reared together Identical twins reared apart Fraternal twins reared together Siblings reared together Unrelated individuals reared together

Genetic Influences With age, genetic influences become more apparent. With age, genetic influences become more apparent. Adopted children’s intelligence scores become more like their biological parents, and identical twins similarities continue to increase as they age. Adopted children’s intelligence scores become more like their biological parents, and identical twins similarities continue to increase as they age. Still hard to tell what percentage of intelligence comes from genes to account for differences between people (heritability). Still hard to tell what percentage of intelligence comes from genes to account for differences between people (heritability).

Genetic Influences years 16 years Child-parent correlation in verbal ability scores Children and their birth parents Adopted children and their birth parents Adopted children and their adoptive parents

Environmental Influences Early Intervention Early Intervention Head Start Head Start Schooling Effects Schooling Effects Schooling and IQ scores tend to correlate Schooling and IQ scores tend to correlate

Schooling Effect Grade 6 Grade 5 Grade Age in months IQ gains relative to grade 4 baseline

Group Differences in IQ Scores Ethnic Similarities and Differences Ethnic Similarities and Differences Racial groups differ in IQ scores Racial groups differ in IQ scores Higher scoring ppl and groups tend to have higher incomes and education Higher scoring ppl and groups tend to have higher incomes and education Individual differences within a race are much greater than differences between races Individual differences within a race are much greater than differences between races Asian students outperform North American student on math tests Asian students outperform North American student on math tests IQ scores have increased IQ scores have increased White and blacks tend to score the same on infant IQ tests White and blacks tend to score the same on infant IQ tests

Group Differences in Intelligence Scores Are Probably Mostly Attributed to the Environment Variation within group Difference within group Poor soilFertile soil Seeds

Group Differences in IQ Scores Gender Similarities and Differences Gender Similarities and Differences No big differences No big differences Girls are better spellers, more verbal, more sensitive to senses Girls are better spellers, more verbal, more sensitive to senses Boys tend to be in lower classes more and talk later and stutter more Boys tend to be in lower classes more and talk later and stutter more Math and Spatial Aptitudes Math and Spatial Aptitudes No huge differences No huge differences Boys tend to do a bit better on math Boys tend to do a bit better on math Girls better on memory and picture recognition Girls better on memory and picture recognition Women better at reading facial expressions Women better at reading facial expressions

The Question of Bias 2 definitions 1. Tests detect not only innate differences in IQ but also differences caused by cultural experiences Yes. Test do not account for differences in cultures, which may make them bias Yes. Test do not account for differences in cultures, which may make them bias 2. Is a test less valid for some groups than for others. No. The predictive value of a standard IQ testS is roughly the same for black and whites and rich and poor……. No. The predictive value of a standard IQ testS is roughly the same for black and whites and rich and poor…….

The Question of Bias Stereotype Threat Stereotype Threat A self confirming concern that one will be evaluated based on a negative stereotype A self confirming concern that one will be evaluated based on a negative stereotype Black student's taking verbal test Black student's taking verbal test Women and math scores Women and math scores