Bibliography (10):

1. A meta-analysis of sex differences in animal personality: no evidence for the greater male variability hypothesis

2. Greater variability in chimpanzee (Pan troglodytes) brain structure among males

3. A Mega-Analysis of Personality Prediction: Robustness and Boundary Conditions

4. Small Effects: The Indispensable Foundation for a Cumulative Psychological Science

5. The reality and evolutionary [importance] of human psychological sex differences

6. Wikipedia Bibliography:

   1. https://en.wikipedia.org/wiki/Variability_hypothesis  :

      https://en.wikipedia.org/wiki/Variability_hypothesis

   2. Meta-analysis

   3. Statistical-significance

   4. Effect size

   5. Observational error