BASIC FACTS ABOUT INTELLIGENCE TESTING SCORES: Once again, modern IQ test scores are based on a normal distribution in which 68% of all scores fall within one deviation above or below the average → raw scores become deviation IQ scores which tell you where you place on a normal distribution of intelligence

BASIC FACTS ABOUT INTELLIGENCE TESTING RELIABILITY: IQ tests are highly reliable, especially in comparison with other psychological tests, with correlations close to +1 → because psychological tests, of which IQ is one, rely on a sample, factors related to a specific test (low motivation, high anxiety) can distort scores

BASIC FACTS ABOUT INTELLIGENCE TESTING VALIDITY: IQ tests are generally valid if the measured entity is academic intelligence, with fairly high correlation between test score and grades → IQ tests are seen as limited in measuring other types of rational, real world thinking and decision- making skills

BASIC FACTS ABOUT INTELLIGENCE TESTING AGE: IQ scores for children under 4 are generally unreliable and not good predictors, but become more consistent as they age → early studies suggested mental abilities generally decline for older adults, but more recent evidence shows fluid intelligence decreasing, but crystallized increasing

BASIC FACTS ABOUT INTELLIGENCE TESTING JOBS: The link between IQ and job status is moderate (however, high IQs are more likely than low to have a high-status job), but weaker for IQ and income → IQ scores and job performance roughly correlate at .50

BASIC FACTS ABOUT INTELLIGENCE TESTING OTHER CULTURES: IQ test us is not universal – many non-Western cultures with different values and conceptions of intelligence don’t rely on them

EXTREMES OF INTELLIGENCE Today the term intellectual disability is used to refer to subnormal intelligence in large part to avoid the demeaning and stigmatizing connotations of previous designations (feebleminded, mentally deficient, mental retardation)

INTELLECTUAL DISABILITY To be considered intellectually disabled means one has limited general mental ability and difficulty adapting to the demands of life → Subnormal mental ability is considered to be an IQ two standard deviations below the mean (or, approximately 70)

INTELLECTUAL DISABILITY → the life (adaptive) skills referred to in the definition (which may be hard to measure precisely, but shift the definition away from a single determinant factor) include: 1. conceptual skills: language use, managing money and time, etc. 2. social skills: making friends, following rules, not being victimized, etc. 3. practical skills: job skills, travel/transportation capability, household skills, etc.

INTELLECTUAL DISABILITY A small % (3 or less) of the population are considered to have some form of intellectually disability ranging from mild to moderate to severe to profound → despite the common (mis)perception that most cases are severe (including involving obvious physical signs), the reality is that the large majority are mild (IQs of 55-70)

INTELLECTUAL DISABILITY Down syndrome is a form of intellectual disability involving mild to severe mental disabilities and physical disorders caused by an extra copy of chromosome 21 → roughly 1,000 causes for intellectual disabilities have been identified, but more than ⅓ of the cases have unknown causes

GIFTEDNESS The concept of giftedness is less defined than that of intellectual disability, with the ideal definition relying on more than just IQ scores → most schools, however, focus primarily on IQ in identifying gifted children, with roughly the top 3% whose IQs are near the 130-mark considered

GIFTEDNESS Do the gifted really fit the stereotype of being frail, socially unskilled introverts with significant emotional problems? → not according to the ongoing study begun by Terman (in 1921!) that has tracked those with IQs over 135: the evidence shows as a group they have above- average physical, social, and emotional health

GIFTEDNESS → other evidence does suggest, however, that those at the extreme high-end DO exhibit signs of unhealthy indicators suggested by the stereotypes

GIFTEDNESS Despite the majority of Terman’s subjects attaining high levels of education and leading successful professional lives, none came to be seen as geniuses → this suggests a 2nd group of giftedness beyond the academic world: those not only with high intelligence, but also with the creativity and motivation to make enduring contributions

GIFTEDNESS So does achievement depend on innate ability or hard work (nature or nurture)? → many psychologists believe that hard work and determination make the difference → Malcolm Gladwell in his book “Outliers” says that in order to become an expert at anything, one must put in 10,000 hours of practice → and the Chinese, who say that one must “eat bitterness” to become better than the rest