The historical and conceptual development of intelligence tests in psychology during the modern period - Essay Example

?The historical and conceptual development of intelligence tests in psychology during the modern period This survey of the historical and conceptual development of intelligence tests in psychology gives insight into how ideas and debates related to them evolved, and identifies changes in conceptual issues to understand how psychological thought developed. These developments are traced from the time of Sir Francis Galton to the present, with a focus on how psychology has become a more scientific discipline over time. According to David Wechsler, intelligence is defined as “The global capacity to act purposefully, to think rationally and to deal effectively with the environment” (Coon, 2009). However, there are differences in approach and conceptions of intelligence have also been changing. Special psychological tests are devised to measure this quality of intelligence. An intelligence test is essentially an instrument designed to indicate how intelligent a person is. Many such tests have been devised, but their purpose is similar: to measure people’s intelligence. Over time however, the concept of psychological testing has been applied in various areas other than intelligence such as personality assessment. The other uses of intelligence tests have been to detect and analyse mental and personality disorders and illnesses. The measure is usually in the form of a score or category. A high score indicates a high degree of intelligence and a low score indicates a low degree. However, this is dependent on the quality of the test. It should therefore be interpreted accordingly. The score’s acceptability is dependent on two important criteria: reliability and validity. Reliability can be checked, for example, by retesting, and validity can be checked, for example, using factor analysis. Anne Anastasi also described an intelligence test as being ‘objective’ and as providing a ‘standardised’ procedure for measuring behaviour (Banerjee, 1994). Thus, many people besides psychologists and psychiatrists, such as teachers and health professionals, also use them. Intelligence is usually measured either for classification, evaluating educational programs, or undertaking scientific investigations. In a classification, the person is indicated as belonging to a certain category. In evaluating programs, the objective is to evaluate its effectiveness. In the case of research or investigations, greater precision is usually required, so the test must be carefully constructed. People also use intelligence tests for self-assessment purposes to gain a better understanding of their intelligence or to compare with others. Most tests nowadays are based on comparing the scores of groups of people. Sir Francis Galton first developed this type of test, known as a norm-based test, in the 1800s. The data is usually interpreted according to a normal frequency distribution (a bell curve). Galton was most likely influenced by physiognomy, as he was interested in other individual differences too, such as head sizes. He focused on reaction times and made various sensori-motor measurements (Wilderdom, 2005). His useful contribution was in demonstrating how measures of central tendency and variability could be used in intelligence testing for describing the data and the concept of correlation. Despite Galton’s specialisation in the psychology of individual differences, importantly, he seems to have overlooked nature factors, such as inherited traits, and nurturing factors, such as education and environmental influences. He was also influenced by Darwin’s theory of evolution and tried to examine it in terms of intelligence (Brysbaert & Rastle, 2009). This early effort was nonetheless a useful start. There are even renewed ‘Galton-like’ approaches being pursued today by the likes of Arthur Jensen and Mike Andersen, so the basic principles continue to be applied. An important new development was the application of these ideas to the field of education when Alfred Binet devised an intelligence test with the help of his colleague Theophile Simon specifically for classifying French students. This was the first proper intelligence test accepted as valid and upon which many later models were based (Brysbaert & Rastle, 2009). The questions related to various tasks so it was comprehensive. It was also arranged according to varying degrees of difficulty, based on the criterion of an average level of performance. A revised version of this original Binet-Simon test was the Stanford-Binet test devised by Lewis Terman at Stanford University. Using this test, students were classified into mental ages and were sought out for whether they could benefit from special instruction. It involved calculating the ratio between the student’s mental and physical ages. The IQ (intelligence quotient) score was obtained by multiplying by 100. This test was adapted for use in the U.S. after it was observed that the original Binet test was unsuitable for Californian students. Thus, devising a universal IQ test is not any easy accomplishment and intelligence tests usually need to be adapted for particular circumstances. The Binet tests were limited in only being able to test one individual at a time whereas a method was required during the First World War for testing groups of people. Thus, a more standardised test was devised by James McKeen Catell, one of Sir Francis Galton’s students. It was also attempted to make the testing process more scientific and therefore more acceptable. In America too, an adapted form of the intelligence test was devised for testing army recruits, and this too was further adapted for testing non-English speaking and illiterate people (Wilderdom, 2005). Two points are noteworthy. Firstly, it becomes necessary to adapt the test according to the context. Secondly, the impact on the war was negligible although it was a major achievement in psychology and set the stage for their adoption, especially in education and business. However, the tests had to be improved further because even at this stage, serious questions were raised over their validity (Gould, 1981). Nowadays, deviation IQ scores are normally used, based on the difference of the individual’s score from the norms for the individual’s age group (Nevid, 2007). Another traditional type of test was the Wechsler Intelligence test devised by David Wechsler, which also classified according to an intelligence scale, in this case separate verbal and non-verbal scales using deviation IQ measures. In contrast to the Binet scales, these tests measured not only verbal but also non-verbal skills so they were not restricted to measuring only a specific type of intelligence. Like Charles Spearman, Thurstone also used factor analysis, but he introduced an important new concept: a multi-factor approach. However, his test is no longer used because it failed to successfully predict performance. Nonetheless, it was a significant development because mental abilities were now seen from a multi-factor perspective instead of generally. Another factorial model was Vernon’s, which was also hierarchical. It is accepted more than the earlier factor based models. These levels designate specific factors as the lowest followed in turn by minor group factors, practical-mechanical ability, verbal-educational ability, major group factors, and the highest level is that of Spearman’s g. Carroll’s model is similar to Vernon’s but has a fewer three levels for cognitive ability. Its advantage is that it views intelligence more broadly instead of how Thurstone and Spearman viewed it, which could be considered extreme. Later, Guilford suggested there were 180 elementary factors, derived from a combination of three important dimensions: contents, operations and products. He refused to accept the existence of a general factor. This model is sophisticated but it has not been influential probably due to impracticality. This highlights the need for psychological tests to be practically implementable; otherwise, they remain only of theoretical interest. Early intelligence tests thus had to be applied differently for different ages. The work of Raymond Cattell proved useful in understanding the differences. He suggested there were two distinct though related components of g, namely fluid and crystallised intelligence, and that whereas the former decreases with age, the latter increases with age. Fluidity is the ability to see relationships and crystallised intelligence develops as knowledge accumulates. Another aspect is that social and cultural contexts need to be taken into account. However, an interesting development in modern psychology is a renewed interest in the physiological basis of intelligence. Whereas, Galton tried to link intelligence with outward physical features, psychologists such as Arthur Jensen and Hans Eysenck are now delving deeper and trying to establish a link with the human nervous system (Gardner, 1993). If electrophysiological measurements are possible, it would take intelligence testing to a new level, independent of the context. However, this could also set a dangerous trend for a renewed interest in eugenics. The broadening scope of thinking on intelligence has led to the more recent theories, which identify not one but multiple different types of intelligences. One of these is Robert Sternberg’s theory, which identifies three intelligences, but the most prominent among them is Howard Gardner’s theory of multiple intelligences in which there are seven. The latter is built upon Thustone’s idea of different packages of intelligence. In Sternberg’s model, the three intelligences are practical, academic and creative. In contrast to Guilford’s model, this model is capable of being put to immediate practical use. Gardner’s model, though popular, has some inconsistencies because the number of intelligences identified has sometimes been less and sometimes even more than seven but it seems as if Gardner is fixated on always specifying seven. Moreover, it is debatable whether some of these can even be identified as intelligence in the sense of cognitive attributes. Some relate more to the affective domain, such as interpersonal intelligence. Regardless, Gardener’s model is very interesting because it breaks the tradition of viewing intelligence narrowly and helps to explain why some people are more intelligent than others in particular respects. The historical overview showed there are various perspectives of intelligence and testing. In the early 19th century, intelligence tests were even used to distinguish between types of mental disabilities and illnesses so they were not only used for measuring intelligence. However, an important theoretical concern over intelligence testing has been it scientific acceptance. In fact, this discipline has had to struggle to be seen as scientific. Comte for example, who was staunchly positivist, regarded psychological methods as so divergent from what he considered scientific that he excluded psychology from his list of scientific disciplines (Nelson, 2009). He regarded psychology as relying heavily on association and introspection, and therefore designated it as a branch of physiology. The historical and conceptual development of intelligence tests demonstrates this transformation perfectly. For example, it was shown that Galton’s physiognomy based theories would not be considered scientific whereas the latest research in electrophysiology of the human nervous system and intelligence is empirically grounded despite the similarities with Galton’s theory. The approach has completely changed. Psychologists have also been increasingly concerned with three important concepts concerning justifying intelligence tests, namely reliability, validity and standardisation. However, a number of issues are preventing intelligence tests from being more widely accepted. The problem is they pose ethical issues. For example, when used for educational placement, they could potentially restrict the child’s growth if the child is placed in an inappropriate category. Other issues arise when intelligence is examined for different genders, cultures, races, heritages, etc. (Maltby et al., 2010). Regarding culture, the main issues are their applicability to different cultures and differing perceptions of intelligence. All the aforementioned theories are based on Western notions of intelligence, yet there are some fundamental differences in the conceptions of intelligence. Sternberg (2000) mentions for example, that whereas Western theorists emphasise the quality of speed in many of the mental tests, other cultures do not. In Buddhist philosophy for example, mental effort is respected very highly, and in some African cultures, speaking less, not more, is regarded more highly. Multiple intelligence theories may be able to explain the differences better as there could be differences in emphasis on the development of particular types of intelligence over others between different cultures. Developments from linking intelligence with physiological factors may also prove useful to further our understanding of intelligence irrespective of contexts. Perhaps the most controversial issue however is eugenics for which Galton is responsible and whose thinking later inspired the Nazis. In ‘IQ: a smart history of a failed idea’, Stephen Murdoch (2007) traces the history of intelligence testing by highlighting its darker side. He mentions Galton was optimistic for eugenics and believed “when common people learned about the inheritability of talent, they would voluntarily cease to have children”. Charles Spearman also advocated granting certain rights to people based on their general intellectual capacity, such as voting rights and even the right to have children. In practice, the science of eugenics has been seriously misused. Their bases have changed, just as intelligence and intelligence testing theories have also changed over time. On the positive side, the historical survey has shown how our understanding of the subject has improved considerably and deepened over time. The focus for the future should be on furthering our knowledge of intelligence in studying individual and social differences and not on using intelligence tests rigidly. The writer believes intelligence is not even a fixed quality as it can change and be developed. People should enquire more deeply to understand human nature and use instruments for classifying people fairly and wisely. References Banerjee, Jyotish Chandra. 1994. Encyclopaedic Dictionary of Psychological Terms. M. D. Publications Pvt. Ltd. Brysbaert, Marc & Rastle, Kathy. 2009. Historical and Conceptual Issues in Psychology. Longman. London. Coon, Dennis. 2009. Psychology: A Journey. 3rd edition. Cengage Learning. Gardner, Howard E. 1993. Frames of Mind: The Theory of Multiple Intelligences. 10th edition. Basic Books. Gould. 1981. In Wilderdom, 2005. Murdoch, Stephen. 2007. IQ: a smart history of a failed idea. John Wiley and Sons. Nelson, James M. 2009. Psychology, Religion, and Spirituality. Springer. Maltby, John; Day, Liz & Macaskill, Ann. 2010. Personality, Individual Differences and Intelligence. 2nd edition. Prentice-Hall. Harlow, Essex. Nevid, Jeffrey S. 2007. Psychology: concepts and applications. Cengage Learning. Sternberg, Robert J. 2000. Handbook of Intelligence. Cambridge University Press. London. Websites Wilderdom. 2005. Key players in the history and development of intelligence and testing. Available at http://wilderdom.com/personality/L1-5KeyPlayers.html [Accessed March 2011]. Read More