Understanding Intelligence and Achievement Testing by Dylan Lane - Provisional Psychologist at PsychMatters, Concord We know from IQ tests conducted on twins that intelligence is, to a large extent, a product of one s genes. Identical twins, who have identical genes, are far more similar in intelligence and personality than non-identical (fraternal) twins. Most estimates put the influence of genes at around 50 percent. Therefore, even if a pair of identical twins grow up in completely different households and environments, they will still be 50 percent similar in intelligence. The other 50 percent is obviously the result of their own unique experiences and upbringing (Pinker, 2003). It is this other 50 percent, the part which can be affected by the environment, which is most important to parents, teachers and psychologists. This is because we can change aspects of a person s environment, but we cannot change their genes. Research indicates that these changes are much easier to make during childhood, while the brain is still developing (Perkins & Grotzer, 1997). For example, large increases in IQ have been found in children who come from homes that provide a lot of encouragement and avoid harsh types of punishment (McCall, Appelbaum, & Hogarty, 1973). Why conduct IQ tests? IQ tests cannot give a complete picture of a person s abilities. They leave out many areas of functioning which people sometimes consider to be signs of intelligence (e.g., musical ability). The particular tasks which make up an IQ test are those which researchers have judged to be particularly relevant and valuable in Western society. In other words, they can predict how well people will perform outside of the testing situation, in various academic and work settings (Groth-Marnat, 2012). So while they cannot provide a complete picture, they do give a good snapshot, or estimate of a person s current intellectual functioning. Furthermore, they tell us a lot about where a person s intellectual strengths and weaknesses lie (Groth-Marnat, 2009; Lichtenberger & Kaufman, 2012). This information about a person s intellectual functioning can be highly useful for psychologists, teachers, employers and even the person them self. For children, this information may help in determining how ready they are for school, what kind of teaching style they might respond to, where their interests will probably lie, and where they may need additional help and training. For adults, IQ testing could give some insight into which occupations they re likely to enjoy or excel at, in order to help them decide on their future career paths. They re also used to assess whether they re ready for work, eligible for disability pensions, and they also help employers, recruiters and even some universities with their recruitment processes (Groth-Marnat, 2009). SPELD NSW E-NEWS Articles 1
Wechsler Intelligence Scale for Children (WISC-IV) A very commonly used test, the WISC-IV is used to examine general intelligence in children and adolescents. It s made up of 10 core subtests and five supplementary ones. The core subtests are used to calculate the full scale IQ score. Within these 10 subtests, are 4 major areas, or indexes. These include the Verbal Comprehension Index; Perceptual Reasoning Index; Working Memory Index and Processing Speed Index. Perceptual Reasoning Index: The core tests which make up this index include block design, picture concepts and matrix reasoning. All of the information in these tests is nonverbal, meaning it does not involve the use of language, reading, speaking or vocabulary at any point. Instead, it examines how people use, organise and reason about visual information. For example, in block design, the child may be shown a two dimensional image of red and white blocks in a particular configuration, and then asked to copy or replicate that image using actual three dimensional red and white blocks. This is a good measure of what s called spatial visualisation ability: the ability to mentally manipulate shapes and three dimensional objects. These visual and spatial skills are very important in everyday tasks and activities. Thus, people who score highly here wouldn t ever have to turn the map book upside down or sideways to see where they were going. You would also require these skills when learning your way around a new environment, merging lanes on the highway, drawing designs, as well as in tasks like packing, where you need to know which objects will fit into various compartments (Groth- Marnat, 2009). Verbal Comprehension Index: The core tests which make up the score on verbal comprehension include vocabulary, comprehension and similarities. In contrast to the perceptual reasoning index, all the tasks are verbal, and look at the person s ability to listen to questions, think and reason with words and express these thoughts. For vocabulary, this might include asking the child/adolescent what a truck or mountain is, or what the word angry means. On tests of comprehension, they might be asked why some people go to work, and the person s answer is graded based on a number of factors or criteria. These tests are good at assessing our ability to form concepts, learn how things relate to one another and make inferences (Lichtenberger & Kaufman, 2012). So people who score highly here would likely express themselves well, understand spoken communication easily, make good conversationalists and do well in verbally-focused occupations (Groth-Marnat, 2009). SPELD NSW E-NEWS Articles 2
Working Memory Index: The core tests on this index include digit span and letter number sequencing. Tests of arithmetic may also be used as an additional or supplementary test. This index examines the person s ability to remember and consciously control verbally presented information, for short periods of time. Being able to hold and organise information in one s mind also requires good concentration skills. For example, in digit span tasks, clients are asked to repeat a string of numbers in the order read out by the examiner (Lichtenberger & Kaufman, 2012). It s important to consider a person s anxiety levels, as high anxiety interferes with the concentration required to complete these tasks. Therefore, people who do well on working memory would likely be good at recalling people s phone numbers, following a sequence of instructions without being distracted, coping with tests and assessments, and may enjoy tasks which require good attention to detail and high concentration skills (Groth- Marnat, 2009). Processing Speed Index: The core tests include coding, while symbol search is often used for a complete processing speed score. These tests look at how quickly one can complete simple tasks with a good degree of accuracy. So in symbol search tests, examinees are shown a group of symbols and asked to indicate the presence or absence of particular symbols, within a certain time limit. To do well, one requires good eye-hand control, motor speed and short-term visual memory (Lichtenberger & Kaufman, 2012). People with different scores on processing speed might find that learning a new task is equally easy, but once it s learnt, the one with higher scores is likely to become much faster at performing the task. High scorers would be fast readers, solve problems quickly and excel in fast paced jobs (Groth-Marnat, 2009). Achievement tests Whereas IQ tests tell us about a person s intellectual potential, achievement tests are focused on what a person has already learnt, or achieved, academically. Achievement tests are mainly used to assist in diagnosing learning disabilities. Typically, this is done by comparing scores on intelligence tests with those obtained on achievement tests. If there s a big difference, or discrepancy, between the scores, this could be indicative of a learning disability (Restori, Katz, & Lee, 2009; Strauss, However, achievement tests can also be used in situations where diagnosing learning disabilities is not the primary aim. Since they give fairly comprehensive insight into where a person s academic strengths and weaknesses lie, they can be used in decisions regarding special education placement, help parents and teachers understand which areas (e.g., reading, written expression, maths) require more assistance, and in devising appropriate curriculums and individual learning plans (Strauss, For people with neurological disorders, achievement tests are often used in conjunction with other tests to estimate how well they might function in their daily lives. This is because everyday activities, such as reading directions or handling finances, require academic skills. Furthermore, the test content is highly relevant to most work environments (e.g., reading rate), and can help determine what kinds of work or academic settings would be more appropriate for clients (Strauss, Sherman & Spreen, 2006). SPELD NSW E-NEWS Articles 3
Wechsler Individual Achievement Test (WIAT) The WIAT is a large battery of tests designed to gauge academic achievement, with the most recent edition called the WIAT-III. In assessing academic achievement, it s intended to assist with diagnosis of learning disabilities, school-readiness, placement decisions and treatment planning. The WIAT was specifically designed to examine the seven areas considered most important in the diagnosis of learning disabilities: word reading, comprehension, mathematics calculations, mathematical reasoning, listening comprehension, oral expression and written expression. The WIAT is highly useful for detecting very low achievement, though it can effectively assess above grade level abilities too (Strauss, Sherman, & Spreen, 2006). The WIAT-III is made up of 4 major components, with 9 subtests. Reading Comprehension: This component includes 3 subtests, word reading, reading comprehension and pseudoword decoding. These tasks assess a wide range of skills, including people s skills in letter identification, accuracy of word recognition, reading rate, oral reading fluency, accuracy and comprehension. Pseudoword decoding involves giving children non-words and asking them to pronounce them. Decoding is one of the most important skills for children to acquire in primary education. A high score on this test would indicate that the child would pick up the spelling and pronunciation of new words quite easily, leading to good reading and verbal skills (Strauss, Written Language: There are two subtests on this component, spelling and written expression. On spelling, early items include hearing a sound and writing the correct letter, while later items form a word dictation task. The written expression test assesses a range of skills, including timed alphabet writing, sentence building and generation, descriptive and persuasive writing - evaluating the vocabulary, organisation and use of themes. Children who do well on these tasks would have no trouble writing stories with a plot and themes, and forming structured, coherent arguments (Strauss, SPELD NSW E-NEWS Articles 4
Mathematics: The subtests in this component are numerical operations and mathematical reasoning. Numerical operations include skills in counting (e.g., counting pennies), calculations, i.e., addition, subtraction etc., fractions and decimals. Mathematical reasoning asks examinees to provide answers, orally, to questions involving math concepts (e.g., time, money, probability). These tasks assess one s ability to do geometry, statistics, estimation, identifying physics, engineering, aviation, finance and economics (Torpey, 2012). Oral Language: This component is made up of listening comprehension and oral expression subtests. Listening comprehension refers to sections dealing with receptive vocabulary, expressive vocabulary and sentence comprehension. Receptive vocabulary tasks use a four-picture test, whereby subjects are shown four pictures and told a word, then asked to decide which picture the word describes best. Expressive vocabulary asks subjects to provide words for a definition which is accompanied by a picture cue. Oral expression tests a number of skills, such as word fluency, a person s auditory short-term memory, and their ability to generate stories, and giving directions, where the child is asked to give detailed directions or steps for performing a specific task (Strauss, References Groth-Marnat, G. (2009). Handbook of psychological assessment (5 th ed). Hoboken, NJ: John Wiley & Sons. Lichtenberger, E. O. & Kaufman, A., O. (2012). Essentials of WAIS-IV assessment. Hoboken, NJ: John Wiley & Sons Inc. Pinker, S. (2003). The blank slate: The modern denial of human nature. London, England: Penguin Books. Restori, Katz, & Lee (2009). A critique of the IQ / achievement discrepancy model for identifying specific learning disabilities. Europe s Journal of Psychology, 4, 128-145. Strauss, E., Sherman, E. M. S., & Spreen, O. (2006). A compendium of neuropsychological tests: Administration, norms, and commentary. Oxford, England: Oxford University Press. Torpey, E. (2012). Math at work: Using numbers on the job. Occupational Outlook Quarterly, 3-13. http://www.bls.gov/ooq/2012/fall/art01.pdf Originally printed in the SPELD NSW June 2014 E-News. SPELD NSW E-NEWS Articles 5