PSYC3020 L6 Individual score Interpretation Part 2 + IQ

We can estimate the 68% confidence interval of an individual's test score by adding and subtracting one Standard Error of Measurement from their score.

True

You can calculate the Standard Error of the Difference between two scores on the same test if you know the reliability of the test and the standard deviation of an appropriate reference sample.

True

You can calculate the Standard Error of the Difference between two scores on the same test if you know the Standard Error of Measurement of that test.

True

To be 95% confident that the difference between two individual scores represents a real difference, they have to differ by at least one Standard Error of the Difference.

False

If two individual scores differ by less than two Standard Error of the Differences then we cannot be 95% confident that there is a real difference between their true scores.

True

If two individual scores differ by less than one Standard Error of the Difference then we cannot be 95% confident that there is a real difference between their true scores.

True

Professor Wrinklebum has an IQ score of 145. He then completes a brain-enhancement therapy session. His IQ score is then re-measured at 155. The IQ test used has a standard deviation of 15 and a test-retest reliability of .90. We CAN therefore be 95% confident that his true IQ scores has actually improved (assuming no practice effects).

False

You have a client who complains your therapeutic intervention to reduce their debilitating statistics-phobia isn't working. They scored 125 on your validated statistics-phobia scale before the intervention, and 110 afterwards. The SEM of the scale is 5. What's the SEdiff and is your client correct?

Not correct. 15 >14.4 => It's working

Binet's original intelligence tests (later adapted for use in the US army) were group-administered.

False

The US army intelligence tests used in the First World War involved an Alpha version for illiterate recruits and those who could not speak English, and a Beta version for recruits literate in English.

False. Other way round

Yerkes, the man behind the First World War US army intelligence tests, argued that intelligence test scores were SOLELY a result of "inborn" intelligence and were not influenced by education at all.

False

Some of the tasks used in the First World War US army intelligence tests demonstrated that many recruits had an actual IQ of zero.

False. Raw scores were 0

The standardisation sample used for the First World War US army intelligence tests was a small sample of students and businessmen selected because they were already KNOWN to have a mental age of 16.

False. 16 was a supposition

The US army intelligence tests of the First World War established the average mental age of white American males as 13.08 years. The most significant problem with the interpretation of this statistic is that an inappropriate standardisation sample was used.

True

One objection to the First World War US Army IQ tests was that white people were found to perform just as badly as other ethnic groups.

False. White people did better than other ethnic groups

Eugenics refers to a movement advocating practices designed to improve the genetic composition of a population.

True

Herrnstein and Murray, in their book "The Bell Curve", used multiple regression techniques to investigate IQ.

True

Herrnstein and Murray, in their book "The Bell Curve", failed to control for Socio-Economic Status (SES) in their analyses of IQ.

False. They did measure SES but some say it was too crude

Based on twin studies cited by Plomin and Spinath (2004), intelligence has been estimated to be about 50% inherited.

True

According to twin IQ correlation data collected by Plomin and Spinath (2004), heritability (i.e., genetics) appears to become MORE of a factor in determining IQ with increasing age.

True

Turkheimer et al. (2003) found that the heritability (genetic component) of IQ appeared to be much higher for upper-middle class individuals than lower class individuals.

True

Environmental multipliers could mean that small genetic effects can account for large individual differences in intelligence.

True

The Flynn effect refers to the finding that IQ scores increase with faster simple reaction time.

False. Nothing to do with reaction time

IQ scores have been found to be associated with family integrity, health status, academic achievement, and law-breaking.

True

The correlation between job performance and IQ is typically in the range of .60 to .80, according to Sternberg and Hedlund (2002).

False. It's .3-.6

Why do we have to add and subtract DOUBLE the SEM from an individual's score in order to get the 95% confidence interval?

The SEM is the estimated standard deviation of a test taker's scores if they were to take a test many times. the 95% confidence interval is plus or minus two standard deviations on a normal curve.

An IQ test (mean 100, SD 15), has a reliability of .98. If an individual gets an IQ score of 105 on that test, what's the 95% confidence interval of their score?

SEM = 2.12

95% CI = 105 +/- 2*SEM

= 101 to 109

What is the Standard Error of the Difference for individual scores used for?

Seeing if 2 scores differ significantly from each other

Describe the two components of the WWI US Army IQ tests.

- Alpha: literates

- Beta: illiterates

What was the difference between Yerkes and Binet's approaches to measuring intelligence, both practically and theoretically?

- Binet: individually administered for education purposes.

- Yerkes: group administered for army purposes.

How could the content of Yerkes' tests be potentially criticized?

- Content was biased towards white Americans

What was suspicious about the distribution of scores obtained from the WW1 army tests?

- Skewed. Lots of 0 scores

How was the average mental age of those who completed the WW1 army tests calculated and what was dodgy about this?

- They used a sample of students and businessmen as the standardised sample who they defined as having "adult intelligence". Dodgy because the sample is not representative of the adult population

Describe the alleged influence of US eugenics policies on Jewish people in the lead up to the Second World War.

- Meant that less Jews were able to come to the USA

What policies did the US government introduce during the 20th century to attempt to increase the overall IQ of the US population?

- Immigration quotas

- Forced sterilisation of disadvantaged groups

What are the key arguments put forward in the controversial 1994 book "The Bell Curve"?

- IQ mostly inherited

- IQ invariant across the lifespan

- Education can't help increase IQ

- IQ group differences

What are the key conclusions made by the controversial 1994 book "The Bell Curve"?

- Society will become stratified by intelligence

What comparison is commonly used to examine genetic contributions to intelligence?

Twin studies (MZ vs DZ twins)

What is the evidence for a significant genetic contribution to intelligence?

DZ correlation for IQ inheritance > MZ (.86 > .6)

What criticisms have been levelled at studies claiming a significant genetic inheritance of intelligence based on twin studies?

- That environment also plays a large role. Genes are not fully deterministic

If IQ is largely inherited, what implications does this have for how easily it can be changed?

That IQ can still be improved by environmental factors

What is the Flynn effect and what theoretical implications does this have for intelligence test scores?

- Average IQ increases by 3 points every decade

- You can't compare scores of today from scores of the past directly.

A man completes an IQ test in 1950 in the UK and scores 95. Thirty years later, in 1980, he completes exactly the same test again (but the test has been re-standardised using a contemporary adult UK sample). He scores 95 again. What can you conclude from this?

He's not as smart as he once was (compared to the average person). His IQ has gone down in real terms.

What real world variables does IQ correlate with?

- Education

- Job performance

- SES and health