Set of lecture notes titled G, regarding Spearman's Theory of Two Factors in relation to mathematical ability, with illustrative diagrams.

The other set of notes relates to this, with further illustrative diagrams including the 9 point circle, and a graph regarding both Scottish Mental Surveys. These are mostly written on the back of minutes from the British Psychological Society business for council meeting, 1951, and minutes from Scottish Council for Research in Education meetings.