Spearman's concept of 'g' stands for –

Charles Spearman's two-factor theory of intelligence holds that performance on any mental task is governed by two components: a single general factor ('g') that operates across all cognitive tasks, and task-specific factors ('s') unique to each particular ability.

In this framework, 'g' denotes general intelligence — the common underlying mental ability that influences performance on every type of cognitive task, distinct from any single specific skill.

• 'Group intelligence' belongs to a different area — the study of collective or team-level performance and dynamics — and is not a term Spearman used in his individual test-score factor analysis.

• 'Genetic intelligence' concerns the hereditary origin of ability, a question about cause; Spearman's factor was derived purely through statistical analysis of test-score patterns, independent of any claim about heredity.

• 'Graded intelligence' evokes a ranking/grading scale; Spearman's theory identifies factors — not ranks or grades — behind test performance.

Hence, Spearman's 'g' stands for general intelligence.