A statistical technique used for a large number of variables to establish whether there is a tendency of groups to be interrelated is

Factor analysis examines a large set of variables to find whether groups of them tend to be interrelated.

It reduces many correlated variables into a few underlying factors or dimensions.

Simple correlation measures the relationship between only two variables at a time.

Multiple correlation relates several predictors to a single outcome, not clusters among many variables.

Regression predicts a dependent variable from one or more predictors rather than uncovering factors.

Factor analysis is widely used to build and validate psychological scales and tests.