Statistics of Culture Fair Numerical Spatial Examination - Final version

Introduction

The scores on this test were provided to me years ago by Etienne Forsström, its constructor. As a result, this sample is complete, and not affected by bias in score reporting by candidates taking tests of mine. There have been several prior versions of this test, and I understand that this final version was formed by leaving out problems from the earlier versions and calculating each candidate's score over the remaining ones. This drastic "pruning" of the test probably explains the block-like shape of the score distribution, with many ceiling and below-threshold scores and no tapering to the high and low end. I do not know if the test has actually been administered in this final form. If so, such would require norms based on those new administrations, because the statistical behaviour of items tends to change when items are placed in a new environment, and norms based on prior versions with more items would likely be too generous for the new administrations.

Scores on Culture Fair Numerical Spatial Examination - Final version (Etienne Forsström) as of 12 January 2026

Contents type: Numerical, spatial.   

• n: 289
• Mean: 8.5
• Standard deviation: 5.05
• Maximum possible: 17
• Male mean: 8.8 (n = 263)
• Female mean: 5.2 (n = 26)
• Proportion of males among candidates: 0.910
• Hardness: 0.50
• Resolution: 3.5

Remark: Do notice that the male/female participation and score differences here are highly similar to what is found for other authors' high-range tests. This suggests that these are genuine behavioral sex differences, and not due to bias in tests from any particular author.

Scores by males

n = 263

Scores by females

n = 26

Correlation of Culture Fair Numerical Spatial Examination - Final version (Etienne Forsström) with other mental ability tests

Weighted mean of correlations: 0.422 (N = 611)

Estimated g factor loading: 0.65

Ranking in above table is based on the unrounded correlations. All available data is present in this table, no tests are left out except for those with less than 4 score pairs. All known pairs are used, including possible floor/ceiling scores or outliers.

Remark: The category "Epiq Tests (aggragate)" in above table includes the earlier versions of the present test, from which the final version was created by leaving out problems. This overlap is inflating that correlation. This also affects the tables below with "Estimated loadings of…" and "Estimated g factor loadings for restricted ranges".

Estimated loadings of Culture Fair Numerical Spatial Examination - Final version (Etienne Forsström) on particular item types

These are estimated g factor loadings, but against homogeneous tests (containing only particular item types) as opposed to non-compound heterogeneous tests. Although tending to surprise the lay person, it is not uncommon for tests to have high loadings on item types they do not actually contain themselves. Such loadings reflect the empirical fact that most tests for mental abilities measure primarily g, regardless of their contents; that the major part of test score variance is caused by g, and only a minor part by factors germane to particular item types. It is of key importance to understand that this is a fact of nature, a natural phenomenon, and not something that was built into the tests by the test constructors.

N = 396

Compound tests have been left out of this table to avoid overlap.

Balanced g loading = 0.63

National means for Culture Fair Numerical Spatial Examination - Final version (Etienne Forsström)

Total number of countries: 31

For reasons of privacy, only countries with 3 or more candidates are included in this table. Ranking is based on the unrounded means, and then alphabetic.

Correlation of Culture Fair Numerical Spatial Examination - Final version (Etienne Forsström) with personal details

Notice: A correlation is generally considered significant if its p value is 0.05 or less.

Estimated g factor loadings for restricted ranges

The goal of estimated g factor loadings for restricted ranges is to verify the hypothesis that g becomes less important, accounts for a smaller proportion of the variance, at higher I.Q. levels. The mere fact of restricting the range like this also depresses the g loading compared to computing it over the test's full range, so it would be normal for these values to be lower than the test's full-range g loading.

Scores by age for Culture Fair Numerical Spatial Examination - Final version (Etienne Forsström)

N = 287

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