Statistics of Mother's educational level

Legenda

The educational levels reported by test candidates are encoded as follows:

• 0 = No formal education
• 1 = A few years primary school
• 2 = Primary school completed
• 3 = A few years secondary school
• 4 = Secondary school completed
• 5 = Bachelor
• 6 = Master
• 7 = Doctor

Scores on Mother's educational level as of 27 March 2025

Contents type: Personal information, observation, or non-cognitive personality test score in numeric form.   

• n: 1098
• Mean: 4.3
• Standard deviation: 1.35
• Maximum possible: 7
• Male mean: 4.3 (n = 961)
• Female mean: 4.3 (n = 135)
• Intersex mean: 2.5 (n = 2)
• Proportion of males among candidates: 0.875
• Hardness: 0.39
• Resolution: 0.5

Scores by males

n = 961

Scores by females

n = 135

Correlation of Mother's educational level with other mental ability tests

Weighted mean of correlations: 0.009 (N = 5837)

Estimated g factor loading: 0.10

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.

Observation: There is no significant correlation on the whole of Mother's educational level with I.Q. test scores.

Correlation of Mother's educational level with other tests - for females

Weighted mean of correlations: 0.143 (N = 146)

Estimated g factor loading among females: 0.38

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.

Observation: While the correlation within females is larger as often, this is not significant.

Estimated loadings of Mother's educational level 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 = 4141

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

Balanced g loading = 0.05

National means for Mother's educational level

Total number of countries: 72

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 Mother's educational level with personal details

Observation: There is an exceedingly significant moderate positive correlation of Father's educational level with Mother's educational level, reflecting assortative mating, one presumes. Virtually the same correlation is seen below for both the female and the male candidates separately, which makes sense given that the assortative mating took place before the candidate (child) was conceived, and can therefore not have been affected by the sex of the candidate. The fact that this correlation is so alike within-sex confirms that it is genuine, and also confirms that the statistic was reported correctly on the whole. The positive correlation with birth year implies that candidates with later birth years have mothers with higher educational levels.

Correlation with personal details of Mother's educational level - within females

Correlation with personal details of Mother's educational level - within males

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.

Remark: These are not significant.

Conclusions

1. There is, on the whole, virtually zero correlation of Mother's educational level with candidate's high-range I.Q. test scores;
2. Within females, however, there is a small positive correlation, but not significant;
3. Only in the lowest ranges of Mother's educational level there seems to be a somewhat higher positive correlation with I.Q.;
4. There is a significant moderate positive correlation of Father's educational level with Mother's educational level, reflecting assortative mating.

General observations

After seeing the statistics of candidate's, mother's, and father's educational levels, the following general observations can be made:

1. There are small positive to near-zero correlations of high-range I.Q. scores with the three indicators of educational level;
2. Only for the lowest few educational levels is the correlation somewhat larger;
3. Within female candidates, the correlations of I.Q. scores with the three indicators of educational level are higher than within male candidates; given that females score a bit lower than males on high-range tests, these higher correlations are consistent with the phenomenon that the correlation of I.Q. with educational level is higher over the full range than in the high range;
4. The correlations with Mother's educational level are lower than those with Father's educational level.

Disclaimer

These reports are based exclusively on statistics of high-range intelligence tests. Over the full range of I.Q. and the general population, the correlations of I.Q. scores with the indicators of educational level are known to be much higher than reported here. Likely, this difference has to do with phenomena like attenuation due to restriction of range, and Spearman's "law of diminishing returns" regarding g.

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