2 Defining Intelligence Global capacity to act purposefully, think rationally, and deal effectively with the environmentOperational Definition: Operations used to measure a conceptAptitude: Capacity for learning certain abilitiesMultiple Aptitude Test: Test that measures two or more abilitiesGeneral Intelligence Test: Test that measures a wide variety of mental abilities
3 Fig Special aptitude tests measure a person’s potential for achievement in a limited area of ability, such as manual dexterity. Multiple aptitude tests measure potentials in broader areas, such as college work, law or medicine. Intelligence tests measure a very wide array of aptitudes and mental abilities
4 Fig.11.2 Sample questions like those found on tests of mechanical aptitude. (The answers are A and the Driver.)
5 ReliabilityReliability: A measure should give the same score each time the same person takes itTest-Retest: Give test to a large group, then give exactly the same test to same group laterSplit-Half: Making sure scores on one-half of a test match the scores on the other half
6 ValidityValidity: Ability of a test to measure what it is purported to measureCriterion Validity: Comparing test scores to actual performanceComparing SAT to college grades
7 Testing IntelligenceNorm: Average score for a designated group of peopleStanford-Binet Intelligence Scale, Fifth Edition (SB5): Widely used individual intelligence test, derived directly from Alfred Binet’s first intelligence test; for ages 2-90!Chronological Age: Person’s age in yearsMental Age: Average intellectual performanceIntelligence Quotient (IQ): Intelligence index; mental age divided by chronological age, then multiplied by 100Average IQ in the USA is 100
8 Fig.11.4 The stability or reliability of IQ scores increases rapidly in early childhood. Scores are very consistent from early adulthood to later middle age. (Source: Schuerger & Witt, 1989.)
9 More IQ TermsDeviation IQ: Scores based on a person’s relative standing in his or her age group; how far above or below average a person’s score is, relative to other scoresIQ scores are not very dependable until a child reaches age 6Terminal Decline: Abrupt decline in measured IQ about 5 years before death
10 Wechsler TestsWechsler Adult Intelligence Test-Third Edition (WAIS-III): Adult intelligence test that rates verbal and performance intelligence and abilitiesWechsler Intelligence Scale for Children-Third Edition (WISC-III): Downscaled version of the WAIS-III; for children aged 6 years to 16 years 11 months, 30 daysSB5 is better suited for children and adolescentsWISC-IV to be published in 2003
11 Wechsler ScalesPerformance Intelligence: Nonverbal intelligence; measured by solving puzzles, completing pictures, and assembling objectsVerbal Intelligence: Language intelligence; measured by answering questions involving vocabulary, information, arithmetic, and other language-oriented tasks
12 Group TestsThese tests can be given to a large group of people with little supervision; usually contain multiple-choice itemsArmy Alpha was the first group intelligence test; developed for those entering World War I in the USANormal (Bell-Shaped) Curve: Most scores fall close to the average, and very few are found at the extremes
13 IQ ResearchMen and women do not appear to differ in overall intelligenceA strong correlation (about .50) exists between IQ and school grades
14 GiftednessHaving a high IQ (usually above 130) or special talents or abilities (playing Mozart at age 5)
15 Mental Retardation (or Developmental Disabilities): Some Definitions Presence of a developmental disability and an IQ score below 70; a significant impairment of adaptive behavior also figures into the definitionAdaptive Behavior: Basic skills such as dressing, eating, working, hygiene; necessary for self-careFamilial Retardation: Mild mental retardation that occurs in homes that have inadequate nutrition, intellectual stimulation, medical care, and emotional support
16 Organic Causes of Mental Retardation Related to physical disordersBirth Injuries: Lack of oxygen during deliveryFetal Damage: Congenital problem; prenatal damage from disease, infection, or drug use by the motherMetabolic Disorders: Disorder in metabolism; affects energy use and production in the bodyGenetic Abnormalities: Abnormality in the genes, such as missing genes, extra genes, or defective genes
17 Types of Organic Causes Phenylketonuria (PKU): Genetic disease in which the child lacks an important enzyme. Allows phenylpyruvic acid to accumulate in the bodyIf untreated, severe retardation may occur by age 3Routine medical tests at birth can detect PKUTreat with phenylalanine-free diet (found, for example, in Aspartame, known as Nutrasweet)
18 More Organic Causes of Mental Retardation Microcephaly: Head and brain are abnormally small; brain is forced to develop in a limited spaceHydrocephaly: Buildup of cerebrospinal fluid within the ventricles (brain cavities); pressure can enlarge the head and damage the brainCretinism: Stunted growth and retardation caused by insufficient supply of thyroid hormoneMay also be caused by lack of iodineEasily detected in infancy
19 Down SyndromeDown Syndrome: Genetic disorder caused by presence of extra chromosome (usually on the 21st pair; trisomy 21); results in mental retardation and shorter life spanDoes not run in the familyOlder a woman is, greater the risk to produce a Down’s childOlder fathers also contribute (about 25% of the time)No cure, but is detectable before birth
20 Fragile X SyndromeFragile X Syndrome: Genetic form of retardation caused by defect in X chromosomeRuns in familiesSex-linked; mainly affects boysMost suffer from hyperactivity and attention disordersBecome more severely retarded as adults
21 Heredity and Environment Eugenics: Selective Breeding for desirable characteristicsFraternal Twins: Twins conceived from two separate eggsIdentical twins: Twins who develop from a single egg and have identical genesMany researchers believe that intelligence is a combination of heredity (genes) and environment (upbringing); contributing percentage of each is not known yet
22 New Ways of Viewing Intelligence Speed of Processing: Brain’s speed and efficiency; how fast you and your brain can process informationInspection Time: Amount of time a person must look at a stimulus to make a correct judgment about itNeural Intelligence: Speed and efficiency of the nervous system; innateExperiential Intelligence: Specialized knowledge and skills acquired over time
23 Fig.11.8 Attempts to measure the speed of mental processing have taken several forms. In this example, the person must make a rapid choice based on the position of a colored stimulus flashed on the computer screen. A faster reaction time is assumed to reflect faster processing of information. In some experiments, brain responses are measured directly, through electrodes attached to the scalp.
24 Fig.11.9 Stimuli like those used in inspection time tasks.
25 New Ways of Viewing Intelligence (cont.) Reflective Intelligence: Ability to become aware of one’s own thinking habitsMetacognitive Skills: Ability to manage one’s own thinking and problem solving efforts
26 Gardner’s Theory of Intelligence: Some Concepts Multiple Intelligences: Theory posed by Howard Gardner that states we have several specialized types of intellectual abilityG-Factor: General ability factor; assumed to explain the high correlations among various intellectual measures
27 Gardner’s Theory of Eight Multiple Intelligences Language: Used for thinking by lawyers, writers, comediansLogic and Math: Used by scientists, accountants, programmersVisual and Spatial Thinking: Used by engineers, inventors, aviatorsMusic: Used by composers, musicians, music critics
28 Gardner’s Theory of Eight Multiple Intelligences (cont.) Bodily-Kinesthetic Skills: Used by dancers, athletes, surgeonsIntrapersonal Skills (Self-Knowledge): Used by poets, actors, ministersInterpersonal Skills (Social Abilities): Used by psychologists, teachers, politiciansNaturalistic Skills (Ability to Understand Natural Environment): Used by biologists, organic farmers
29 A Different Type of Intelligence Test Culture-Fair Test: Test designed to minimize importance of skills and knowledge that may be more common in some cultures than in others
30 Fig. 11. 10 No intelligence test can be entirely free of cultural bias Fig No intelligence test can be entirely free of cultural bias. However, culture-fair intelligences test try to minimize the effects of growing up in various cultures. The following sample items are from a culture-fair test. 1. Which pattern is different from the remaining four? (Number 3.) 2. Which of the five figures on the right would properly continue the three on the left_that is, fill in the blank? (Number 5.) 3. Which of the figures on the right should go in the square on the left to make it look right? (Number 2.) 4. At left, the dot is outside the square and inside the circle. In which of the figures on the right could you put a dot outside the square and inside the circle? (Number 3) (Courtesy of R.B. Cattell).
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