PSYC 100
Monday, January 28th, 2013
Assignment 5 – What Determines our Intelligence? The comprehensive concept of intelligence has been studied for several years. Psychologists have collected an incredible amount of research and data in order to determine a person’s intelligence. However, throughout this time, the concept of intelligence has been constantly disputed due to the debate that psychologists refer to as “Nature vs. Nurture.” The Nature side evidently focuses on genetic influences whereas the Nurture side presents environmental influences. In order to most successively assess the concept of intelligence, one cannot simply refer to the aspect of genetics. It is impossible to solely base intelligence on genetics due to the fact that there are multiple environmental influences that continually affect an individual through development: family, friends, school, diet, society, etc. All of these factors are crucial in determining one’s intelligence as they can seriously alter his or hers state of mind. With that said, our environment is more important when it comes to determining our intelligence.
When it comes to determining "how we are intelligent,” intelligence measurements are required. The Binet-Simon intelligence scale, developed by French psychologists Alfred Binet and Theodore Simon, involved the study of children to evaluate their performance (mental age) at a given chronological age. This was used to calculate a child's learning potential. Lewis Terman of Stanford University revised the Binet scale in 1916. The revised scale, called the Stanford-Binet intelligence scale, introduced the concept of the intelligence quotient (IQ). The 1986 revision of the test, the latest of several, was altered, making it useful for adults as well as for children. An individual's score for the correct answers is compared to a table of scores of test takers of the same age (with the average score scaled to 100). Lastly, David Wechsler developed the Wechsler Adult Intelligence Scale (WAIS) in 1939, revised as the WAIS-R. Wechsler also developed the Wechsler Intelligence Scale for Children (WISC), revised as the WISC-R. The revised forms of these scales are still widely used as they contain two sub-scales, verbal and performance, which provide a verbal IQ and a performance IQ – the subscales are then combined for the total IQ. Environmental factors thus play a crucial role in intelligence tests as they primarily evaluate crystalized intelligence.
Crystallized intelligence involves learned or experienced knowledge, making the environment that exposed the individual to that knowledge more important when determining one’s intelligence. On the other hand, evidence shows that recent IQ tests often include multiple factors, which involve both fluid and crystallized intelligence. Fluid intelligence engages one’s ability to independently solve problems however some psychologists deem fluid intelligence as “trainable,” indicating that cognitive theory can be applied to train the brain to become more efficient in the area of fluid intelligence. Consequently, this gives a greater advantage to the Nurture debate as the brain, even in the area of fluid intelligence, is being altered by environmental factors.
The adequacy of a measurement is represented by its reliability and validity. In the case of intelligence testing, reliability is assessed by the correlation between the scores people receive on the same measurement on two different occasions (perfect reliability is 1.0). High reliability is achieved by means of standardized test administration and objective scoring. All test takers are exposed to the same conditions during testing, and all test givers score responses in the same way. The validity of an intelligence test is assessed by the strength of the correlation between test scores and criterion (an independent measure of the variable that is being assessed). There is no single criterion measure with which to assess validity,