-------------------------------
Fruit-and-vegetable diet
Speed
:
high
Fluid intelligence
:
excellent
Sizeable text items
:
so-so
Errors
:
few
Antidepressant diet
Speed
:
good
Fluid intelligence
:
good
Sizeable text items
:
good
Errors
:
few
Modified high-protein diet
Speed
:
good
Fluid intelligence
:
good
Sizeable text items
:
excellent
Errors
:
few
Depressant diet
Speed
:
low
Fluid intelligence
:
So-so
Sizeable text items
:
good
Errors
:
few
Mixed diet (contains junk food)
Speed
:
good
Fluid intelligence
:
So-so
Sizeable text items
:
good
Errors
:
many [
998
]
The fruit-and-vegetable diet increases information processing speed and improves fluid intelligence (mental clarity). To obtain a significant benefit, you need to stay on this diet for 2 days before and on the day of the test. Although I stated in Chapter One that the ancestral diet will improve intelligence after 4-7 days, I chose this length of time in the interest of more rigorous testing of the theory. In practice, the “smart diets” produce noticeable improvements in my thinking after 2 or 3 days. An adapted cold shower every morning and just before an intelligence test will boost fluid intelligence further. I have never taken an official IQ test, although the GRE General test that I took in 1998 correlates strongly with intelligence tests [
20
-
22
]. My experience with online IQ tests suggests that the approach outlined above is effective. Keep in mind that the fruit-and-vegetable diet is not useful for studying for the tests because attention control is low. If you choose to study and prepare for an intelligence test as described below, you may consider using the modified high-protein diet during the preparation phase. Before and during the test you can use the aforementioned “high-speed diet.”
With respect to crystallized intelligence, that is, general knowledge and skills, there is no easy way of increasing it quickly. Nonetheless, it is possible to improve special skills related to the test in question within a short period of time. You can achieve this by familiarizing yourself with the contents of past tests and by practicing taking those sample tests. For example, when I was preparing for the GRE (Graduate Record Examinations) General test in 1998, I bought the GRE Big Book. The latter is a huge tome containing lots of real-life tests from past years, with correct answers at the end of the book. GRE General is a test that students have to pass in order to enter graduate school, such as a Ph.D. or a Master’s degree program at a university in the United States. I took a vacation for one month in July 1998 and did nothing but take those tests from dawn till dusk the whole month. I do not remember right now, but I think I made one or two passes through the Big Book. I used the balanced high-protein diet during that month. Because I was going to take a computer-adaptive test in November of 1998, I also practiced taking the computer-based GRE General (using official practice software) for several days just before the test. These specific test-taking skills, along with academic knowledge that I had accumulated over the previous years, helped me to ace the official GRE General test (see
Appendix VI
).
I got sick before another test, TOEFL (Test of English as a Foreign Language), which was coming up on November 26. I practiced for that test too, but my listening comprehension was so-so and I wasn’t feeling well on the day of the test. In the end, I did OK on the TOEFL, but I am convinced that in the reading comprehension section, some multiple-choice questions contained two correct answers instead of one. I had encountered this peculiarity in the practice TOEFL tests from past years. This section of TOEFL was easy for me: it is nothing compared to the verbal section of the GRE General, which tests language skills of native speakers of English. Nonetheless, I had to guess on several of those “trick questions” and achieved a score of 28 on reading comprehension instead of the highest score of 30. To sum up, practicing taking certain types of tests is going to improve your score, even if your level of knowledge and fluid intelligence remain the same.
I have never taken a proctored IQ test, although I did tinker with internet IQ tests. The Graduate Record Examinations (GRE) General test that I took in November of 1998 correlates well with intelligence tests. I got the following scores (see
the end
of Appendix VI): 99th percentile quantitative section, 99th percentile verbal section, and 98th percentile analytical. These GRE scores correspond to an IQ score above 150 (99.9th percentile) according to some calculations that I found on the Web. There are no recent peer-reviewed studies that compare the GRE General test with IQ tests. One study shows that SAT scores correlate strongly with intelligence [
20
]. Two other reports show that high SAT scores correlate with high intelligence and predict high GRE scores [
21
,
22
]. If you have to take a proctored IQ test as an occupational requirement, and wish to prepare for the test, my advice is to not put too much credence in internet IQ tests. This is because most of them do not measure IQ accurately and have little in common with official IQ tests. In general, you are not supposed to be preparing for an IQ test because intelligence tests are designed to measure mental abilities that people cannot change easily, such as general knowledge and fluid intelligence. Yet studies show that IQ scores can increase by several points with repeated taking of intelligence tests [
499
]. Therefore, you may be able to improve your IQ score to some extent by practicing taking the tests. Some readers may consider this approach “cheating.” In my view, practicing before any tests is fair game, except when you take the same test several times and report the score from your last test as your first-time score. This will be real cheating. Repeated taking of IQ tests will not improve fluid intelligence and brain function in general. This approach will improve the specific skills related to IQ tests. Recent studies show that mental exercises do not improve brain function [
917
,
918
]. In particular, they have no effect on working memory, processing speed, attention function, and fluid intelligence, and there is no reason that they should. Expecting mental exercises to improve brain function is similar to trying to improve computer hardware by loading more software on it and by making the computer work harder than usual—a futile exercise.
As for the preparation routine for an IQ test, first, you need to find out, if you can, what kind of intelligence test you will have to take. There are several scientifically validated tests of intelligence, the most common being Stanford-Binet Intelligence Scales and Wechsler Adult Intelligence Scale. These two tests are common in English-speaking countries and, in non-English-speaking countries, other types of validated IQ tests may be more common. If you know the name of the test, you can then find a description of the test and find books and websites that contain sample questions from past tests. By working through hundreds and thousands of practice questions, you will improve your test-taking skills and are likely to increase your IQ score.
It is also possible that you will not be able to find out what kind of intelligence test you will receive. In this case, if time allows, you can take any official intelligence test (GRE General or SAT will do too) and then practice various test questions from books about intelligence tests. This practice will improve your test-taking skills and will slightly improve your performance on the upcoming intelligence test. Keep in mind that this approach will not increase your intelligence, but rather, it will increase your IQ score. Therefore, if you want to find out your true level of intelligence, the best way is to take a proctored IQ test unprepared.
Some test items such as testing of short-term memory (working memory) may seem impossible to prepare for. A popular type of working memory tests is the forward and backward digit-span task. This task consists of showing a test-taker a sequence of single-digit numbers with an interval of one second between the numbers. The number of digits in the sequence increases (from one up to 10) until the participant fails in two consecutive attempts to recall the same digit span length. The test taker should recall the whole sequence of numbers in direct order (forward digit span) or in reverse order (backward digit span). The maximum length of a sequence that a person recalls correctly is the result of the digit span task. On average, healthy people are able to recall the maximum strand of 7 digits in the forward digit span and 5.5 digits in the backward digit span [
500
]. Based on my experience with practice tests on the Internet, your performance on the digit span task will improve by 1 or 2 points if you use the following technique. Say silently (repeat to yourself) the sequence of numbers as fast as you can. Continue repeating the growing sequence of numbers to yourself until you see the question about the sequence. This technique can improve memorization and can improve performance on tests of short-term memory, such as verbal recall and digit span tasks. Please note that this approach will not improve your working memory; it can only improve your scores on working memory tests.
Those readers who are skeptical about the effectiveness of my dietary techniques may consider using a simple approach. It consists of using your usual routine plus taking an adapted cold shower immediately before an intelligence test. This method is also the easiest to test in a controlled scientific study (warm showers may serve as a control). The performance on the test should improve due to increased fluid intelligence and processing speed [
362
,
924
]. Moderate cooling shares many similarities with stimulant drugs. Stimulants such as coffee and
Ritalin
® improve alertness, processing speed, and attention in healthy people [
358
]. One study shows that brief cooling of the body improves performance of complex (but not simple) mental tasks in healthy volunteers [
362
]. These data point to the improvement of fluid intelligence as a result of moderate cooling.
If you have never used coffee for boosting your performance on tests and if you dislike cold showers, then you may consider having a cup of strong coffee before a test. This will be an easy and legal way to enhance your cognitive abilities. Coffee may not be beneficial for people whose mental abilities are above average and for people who feel nervous or agitated. Adapted cold showers will be beneficial for people who feel nervous or fearful, but will not be beneficial for someone who feels euphoric or overactive. Don’t use adapted cold showers with coffee as this combination can cause hyperactivity or restlessness. Finally, hot showers or hot baths (or a hot environment) tend to worsen performance on tests due to the following temporary effects: increased fatigue, reduced alertness, and reduced processing speed [
352
,
651
,
924
].