What are IQ tests really measuring?
(Medical Xpress) -- When the average person thinks of an IQ test, they think of a measurement of intelligence. A test designed to find those of high intelligence who will go on to succeed in academics and employment. While the question has long been debated by researchers as to what exactly the IQ test measures, a new study shows that intelligence may not be the main focus, but a persons motivation as well.
Published in the Proceedings of the National Academy of Sciences, psychologist Angela Lee Duckworth from the University of Pennsylvania reports her findings on how motivation levels seem to affect IQ results.
The report looks at two studies performed by Duckworth and her team. In the first study they combined the results from 46 previous studies where monetary incentives were used in IQ testing for meta-analysis. This combination brought together more than 2000 subjects. The ranges of monetary incentives were from $1 to $10 or more. Researchers used a statistical parameter called Hedges g to indicate the effects (g values 20 IQ points). On the opposite side of the spectrum, those receiving less than $1 incentive were only 0.1 effective.
In the second study they examined a previous study of 500 boys in Pittsburgh, Pennsylvania who were given IQ tests in the late 80s. The average age of the boys was 12.5 years old. During the IQ test, they had been videotaped and those trained to detect signs of boredom had evaluated the tapes and assessed each boy a motivational score.
By creating a series of computer models of the data, the team discovered that those with a higher motivational score achieved a higher IQ score and the prediction of later success in life held true. These differences in motivational score accounted for up to 84% of the difference in years of school they completed, however only 25% of the differences relating to how well they had done in school during their teenage years.
More information: Role of test motivation in intelligence testing, PNAS, Published online before print April 25, 2011, doi: 10.1073/pnas.1018601108
Intelligence tests are widely assumed to measure maximal intellectual performance, and predictive associations between intelligence quotient (IQ) scores and later-life outcomes are typically interpreted as unbiased estimates of the effect of intellectual ability on academic, professional, and social life outcomes. The current investigation critically examines these assumptions and finds evidence against both. First, we examined whether motivation is less than maximal on intelligence tests administered in the context of low-stakes research situations. Specifically, we completed a meta-analysis of random-assignment experiments testing the effects of material incentives on intelligence-test performance on a collective 2,008 participants. Incentives increased IQ scores by an average of 0.64 SD, with larger effects for individuals with lower baseline IQ scores. Second, we tested whether individual differences in motivation during IQ testing can spuriously inflate the predictive validity of intelligence for life outcomes. Trained observers rated test motivation among 251 adolescent boys completing intelligence tests using a 15-min thin-slice video sample. IQ score predicted life outcomes, including academic performance in adolescence and criminal convictions, employment, and years of education in early adulthood. After adjusting for the influence of test motivation, however, the predictive validity of intelligence for life outcomes was significantly diminished, particularly for nonacademic outcomes. Collectively, our findings suggest that, under low-stakes research conditions, some individuals try harder than others, and, in this context, test motivation can act as a third-variable confound that inflates estimates of the predictive validity of intelligence for life outcomes.
© 2010 PhysOrg.com
- Pesticide exposure linked to lower IQ Mar 24, 2006 | not rated yet | 0
- IQ testing for obese people is challenged Jan 23, 2007 | not rated yet | 0
- Intelligent children more likely to become vegetarian Dec 15, 2006 | not rated yet | 0
- Lower IQ found in children of women who took epilepsy drug May 03, 2007 | not rated yet | 0
- Ability to process information as a baby continues into adulthood Aug 07, 2009 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Why is zone 1 in liver more prone to ischemic injury?
May 23, 2013 Hi, Is it because around central vein, there is only deoxygenated blood from the vein where as in the periphery there is hepatic artery. Also why...
How can there be villous adenoma in colon, if there are no villi there
May 22, 2013 As title suggest. Thanks :smile:
How can there be a term called "intestinal metaplasia" of stomach
May 21, 2013 Hello everyone, Ok Stomach's normal epithelium is simple columnar, now in intestinal type of adenocarcinoma of stomach it undergoes "intestinal...
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013 From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
- More from Physics Forums - Medical Sciences
More news stories
(HealthDay)—We've all seen them: the surfers who race to the beach when a hurricane hits, the guy who decides to ride out the storm in his overmatched boat, the tornado chasers who fearlessly steer their ...
Psychology & Psychiatry 10 hours ago | not rated yet | 0
Women at a particular stage in their monthly menstrual cycle may be more vulnerable to some of the psychological side-effects associated with stressful experiences, according to a study from UCL.
Psychology & Psychiatry 11 hours ago | 3.7 / 5 (3) | 0 |
Ernie Pyle – an iconic war correspondent in World War II – reportedly said "There are no atheists in foxholes." A new joint study between two brothers at Cornell and Virginia Wesleyan found that only ...
Psychology & Psychiatry 14 hours ago | 2.5 / 5 (4) | 1
(Medical Xpress)—Research by Stanford scholar Emma Seppala at the Center for Compassion and Altruism Research and Education found that post-traumatic stress disorder decreased in veterans who participated ...
Psychology & Psychiatry 14 hours ago | 5 / 5 (1) | 0
(Medical Xpress)—Patients with diabetes who are depressed are much more likely to develop episodes of dangerously low blood sugars, or hypoglycemia, than are those who are not depressed, a new study has ...
Psychology & Psychiatry 15 hours ago | not rated yet | 0 |
(Medical Xpress)—A new study by researchers in the US has shown that an ancient virus can be modified to help in the fight against the simian immunodeficiency virus SIV, which is the equivalent in monkeys ...
14 hours ago | 5 / 5 (3) | 0 |
Two mutations central to the development of infantile myofibromatosis (IM)—a disorder characterized by multiple tumors involving the skin, bone, and soft tissue—may provide new therapeutic targets, according to researchers ...
9 hours ago | 3 / 5 (2) | 0 |
Biological processes are generally based on events at the molecular and cellular level. To understand what happens in the course of infections, diseases or normal bodily functions, scientists would need to ...
12 hours ago | 5 / 5 (3) | 0 |
Talking on a hands-free device while behind the wheel can lead to a sharp increase in errors that could imperil other drivers on the road, according to new research from the University of Alberta.
8 hours ago | not rated yet | 0
How can healthy people who hear voices help schizophrenics? Finding the answer for this is at the centre of research conducted at the University of Bergen.
14 hours ago | 4 / 5 (2) | 2
(Medical Xpress)—The way Alzheimer's disease is portrayed by advocacy groups and the media is having undue influence on the euthanasia debate, according to a Deakin University nursing ethics professor.
15 hours ago | not rated yet | 2