Appendix: Introduction to Statistics

Given that much of the debate surrounding intelligence is based on statistical analysis, this outline is inserted by way of being a basic primer for those interested. Statistics is a branch of mathematics dealing with the collection, analysis and interpretation of data, which allows the data to be organised and presented in a way that helps facilitate a better understanding of any patterns in the data. In this context, statistics has developed two methodologies, i.e. descriptive and inferential, that first attempts to summarize the data using techniques like standard deviation and then, second, to draw conclusions about the nature of the data. However, the scope of this discussion is only intended to be a brief introduction in support of the wider discussion of IQ and its social implications.

Frequency Distribution

A frequency distribution may simply be described as a table listing each value of some variable and the number of times it occurs in a given dataset. We might introduce the idea of a frequency distribution by way of an example of ‘height’ within some given population.

 If the people were lined up in order of height, we might expect that the line would take the shape of a distribution, if those of the same height stood in rows as illustrated right. While we might readily see a distribution pattern in the diagram, it does not necessarily help us to quantify the variation in the data. However, this then requires the introduction of two other discussions:

  1. Distribution and Standard Deviations
  2. Correlations and Regression