Sex Differences in Variability in General Intelligence: A New Look at the Old Question

@article{Johnson2008SexDI,
  title={Sex Differences in Variability in General Intelligence: A New Look at the Old Question},
  author={Wendy Johnson and Andrew D. Carothers and Ian J. Deary},
  journal={Perspectives on Psychological Science},
  year={2008},
  volume={3},
  pages={518 - 531}
}
The idea that general intelligence may be more variable in males than in females has a long history. In recent years it has been presented as a reason that there is little, if any, mean sex difference in general intelligence, yet males tend to be overrepresented at both the top and bottom ends of its overall, presumably normal, distribution. Clear analysis of the actual distribution of general intelligence based on large and appropriately population-representative samples is rare, however… 

A Role for the X Chromosome in Sex Differences in Variability in General Intelligence?

  • W. JohnsonA. CarothersI. Deary
  • Biology, Psychology
    Perspectives on psychological science : a journal of the Association for Psychological Science
  • 2009
TLDR
The expected ratios of males to females at various points in the distribution are explored and the proportion of variance in general intelligence potentially due to genes on the X chromosome is estimated, providing clues to the extent to which biologically based sex differences could be manifested in the environment as sex differences in displayed intellectual abilities.

A Key Characteristic of Sex Differences in the Developing Brain: Greater Variability in Brain Structure of Boys than Girls

TLDR
Findings move beyond mean levels by showing that sex differences were pronounced for variability, thereby providing a novel perspective on sex differences in the developing brain.

Sex Differences in Variability in Vocational Interests: Evidence from Two Large Samples

Greater male variability has been established in cognitive abilities and physical attributes. This study investigated sex differences in variability in vocational interests with two large samples (N

Sex Differences in Intelligence: The Developmental Theory

It is a paradox that males have a larger average brain size than females, that brain size is positively associated with intelligence, and yet numerous experts have asserted that there is no sex

Sex Similarities and Differences in Intelligence in Children Aged Two to Eight: Analysis of SON-R 2–8 Scores

TLDR
The results suggest that girls tend to mature earlier with respect to cognitive abilities and IQ scores during the course of development, however, the differences between girls and boys may become negligible.

Gender differences in variance and means on the Naglieri Non-verbal Ability Test: data from the Philippines.

TLDR
Results on mean score differences support the hypothesis that there are no significant gender differences in cognitive ability, and the unusual results regarding differences in variance and the male-female proportion in the tails require more complex investigations.
...

References

SHOWING 1-10 OF 76 REFERENCES

Sex differences in variance of intelligence across childhood.

Consistencies in Sex Differences 1 Running Head : SEX DIFFERENCES ON THE COGNITIVE ABILITIES TEST Consistencies in Sex Differences on the Cognitive Abilities Test across Countries , Grades , and Cohorts

Recently, Strand, Deary, and Smith (2006) reported sex differences for over 320,000 students 11-12 years old on the Cognitive Abilities Test. Although mean differences were small, score distributions

Sex Differences in Intelligence and Brain Size: A Developmental Theory.

The distribution of intelligence.

  • C. Burt
  • Psychology
    British journal of psychology
  • 1957
TLDR
This paper argues that, provided samples are sufficiently large and complete, frequency-curves obtained exhibit small but significant deviations from strict normality, and, for most practical purposes, resulting distributions can be treated as approximately normal.

Sex differences in cognitive abilities test scores: a UK national picture.

TLDR
Boys tend to be both the lowest and the highest performers in terms of their reasoning abilities, which warns against the danger of stereotyping boys as low achievers.

Sex Differences in Variability in Intellectual Abilities: A New Look at an Old Controversy

Contemporary research on sex differences in intellectual abilities has focused on male-female differences in average performance, implicitly assuming homogeneity of variance. To examine the validity

Is Intelligence Distributed Normally

Frequency distributions obtained on applying intelligence tests to large samples of the school population are analysed, and compared with those given by the formulae for the commoner types of

Sex differences in mental test scores, variability, and numbers of high-scoring individuals.

TLDR
An analysis of mental test scores from six studies that used national probability samples provided evidence that although average sex differences have been generally small and stable over time, the test scores of males consistently have larger variance.
...