Measuring interrogative suggestibility with the Italian version of the Gudjonsson Suggestibility Scales (GSS): Factor structure and discriminant validity

• The GSS are instruments used to measure interrogative suggestibility.
• We aimed to provide a systematic evaluation of the validity and reliability of GSS.
• GSS 1 and GSS 2 have an acceptable internal consistency.
• We ran EFA and CFA to evaluate the factorial structure of each subscale of GSS.
• The GSS discriminate interrogative suggestibility from relevant psychological constructs.

The current paper provides an examination of the factor structure and discriminant validity of the Gudjonsson Suggestibility Scale (GSS 1) and of its parallel form (GSS 2), as measures of interrogative suggestibility. In Study 1, we administered the two instruments to large Italian normative samples and we run Confirmatory Factor Analyses to evaluate the factorial structure of the subscales of GSS (Yield 1, Yield 2, and Shift). In Study 2, the GSS were administered together with cognitive, personality and affect measures. A three-factor solution was proposed to account for the factorial structure of both GSS 1 and GSS 2. This solution is consistent with the theory according to which the suggestive items of Yield 1, Yield 2 and Shift subscales correspond to separate aspects of the general construct of interrogative suggestibility. Furthermore, the results of the present research confirm that GSS 1 and GSS 2 satisfactorily discriminate interrogative suggestibility from cognitive, personality and affect constructs.