You may wonder why I have stooped to the filthy practice of ripping off the gullible public. Although described as gullible, they are bright enough to know that there is advantage to being brighter, and are willing to pay for intelligence boosting techniques. Their gullibility, such as it is, is based on believing that most people are honest, and that nice people would not be offering brain training unless it honestly conferred an advantage.
As we know only too well, these training techniques don’t work, and at best have only very limited and circumscribed benefits. Furthermore, there are so many salesmen offering such training courses that you may wish to restrain me not on moral grounds but simply because my efforts will be wasted. The most plausible salesmen, traffickers in hope, have already got the ear of governments, and ready access to taxpayer’s funds, so I am far too late to make my millions.
Thank you, but in this case the $75 is going the other way. That is to say, will intelligence test-taking performance increase if people are paid $75 to do well on the test? This is an interesting question, because critics of intelligence testing have argued that some groups get low scores because they are not interested in the test, and can’t see the point of solving the problems. Perhaps so, although if you don’t get motivated by trying to solve problems that might be diagnostic in itself.
Gilles Gignac decided to have a look at this argument, seeing whether the offer of winning $75 Australian dollars boosted intelligence test scores in university students. For once, I am not too bothered by the subjects being university students, because they tend to have modest funds and healthy appetites. $75 buys 30 tinnies of beer, or 13 bottles of cheapish wine. Enough said.
A moderate financial incentive can increase effort, but not intelligence test performance in adult volunteers. Gilles E. Gignac, School of Psychology, University of Western Australia, Crawley, Western Australia, Australia
British Journal of Psychology (2018)
The setup was detailed, using a counter-balance design, and the end results are pretty clear:
We conducted an experiment with 99 adult volunteers who completed a battery of intelligence tests under two conditions: no financial incentive and financial incentive (counterbalanced). We also measured self-reported test-taking importance and effort at time 1 and time 2. The financial incentive was observed to impact test-taking effort statistically significantly. By contrast, no statistically significant effects were observed for the intelligence test performance scores. Finally, the intelligence test scores were found to correlate positively with both test-taking importance (rc=.28) and effort (rc=.37), although only effort correlated uniquely with intelligence (partial rc=.26). In conjunction with other empirical research, it is concluded that a financial incentive can increase test-taking effort. However, the potential effects on intelligence test performance in adult volunteers seem limited.
There is one set of tasks where being paid to do them seems to have an effect. These are simple, repetitive processing tasks, as shown in Table 1 below.
By the way, this is not to say that processing tasks are a bad measure of intelligence. Under normal circumstances they work fine, but they can be influence by rewards in a way that more g loaded tasks cannot be.
Clear evidence for the contention that intelligence test scores are, to some appreciable degree, invalid due to individual differences in test-taking motivation remains to be reported, at least for adult volunteer samples. Consequently, the substantial validity coefficients reported in the literature supporting the interpretation of IQ scores may not be as biased upwardly as some have suggested, based on analyses of non-adult samples (e.g., Duckworth et al., 2011). As absence of evidence is not evidence of absence, we encourage more research to help understand precisely why test-taking motivation and intelligence test scores are correlated positively in both children and adults.
One reason why test-taking motivation is correlated with intelligence test scores may be that bright people like solving problems. If they have to take a test, they look forward to it, knowing they usually do well, and are interested in finding out precisely how well they do. Less able students don’t like tests, and particularly get discouraged when they relate to difficult subjects.