Statistics of Disorders

Introduction

For many years, candidates have been asked to report whether any psychiatric disorders occur in them. Below are the available statistics of that field, when "yes" is coded as 1 and "no" is coded as 0. In addition, the value of 2 has been assigned to candidates in whom serious disordered behaviour has been directly observed by the test scorer.

Scores on Disorders (own) as of 28 January 2023

Contents type: Personal information and/or observation.   

• n: 1138
• Mean: 0.29
• Standard deviation: 0.49
• Range: 2.0
• Maximum possible: 2
• Male mean: 0.29 (n = 982)
• Female mean: 0.29 (n = 152)
• Unknown sex mean: 1.00 (n = 4)
• Proportion of males among candidates: 0.863

Notice that the male and female means are about equal.

Scores by females

n = 152

Scores by males

n = 982

Correlation of Disorders (own) with other mental ability tests

Weighted average of correlations: -0.112 (N = 5528, weighted sum = -618.22)

Conservatively estimated minimum g loading: -0.33

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.

This negative correlation of disorders with I.Q. test scores and g is a long-standing observation. Given this long history and this huge amount of data, it seems safe to conclude now that -.33 is about the real value of the g loading of having a psychiatric disorder, at least on high-range tests. Over the full range of intelligence, g loadings are generally larger than in restricted ranges due to the statistical phenomenon of attenuation through restriction of range, so that in society at large it must be feared that those with psychiatric disorders have an even greater disadvantage on g-loaded tasks than this -.33 value suggests.

Correlation of Disorders (own) with other tests - for females

Weighted average of correlations: -0.154 (N = 139, weighted sum = -21.46)

Conservatively estimated minimum g loading among females: -0.39

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.

Estimated loadings of Disorders (own) 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 = 3849

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

Balanced g loading = -0.33

National means for Disorders (own)

For reasons of privacy, only countries with 2 or more candidates are included in this table. Ranking is based on the unrounded means, and then alphabetic.

Correlation with national I.Q.'s of Disorders (own)

Correlation of this test with national average I.Q.'s published by Lynn and Vanhanen:

• r = 0.05 (n = 1127)

Correlation of Disorders (own) with personal details

The Gifted Adult's Inventory of Aspergerisms and Disorders in parents and siblings are the best predictors of disorders. The zero correlation with Sex reflects the fact that the sexes have equal means.

Correlation with personal details of Disorders (own) - within females

Correlation with personal details of Disorders (own) - within males

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