Which technique would psychologists use to assess whether a cluster of characteristics that includes ambition, determination, persistence, and self-reliance reflects a single personality trait?

Factor analysis

Explanation:

Factor analysis: The term factor analysis is a statistical technique which is being used to lessen a large number of variables into small numbers of factors.

The technique takes out the maximum number of similar variance from all the given variables and grouped them into a common score and a researcher can use the common score for future analysis.

In the question above, psychologists would use factor analysis technique.