Five reinforcement sensitivity theory (RST) of personality questionnaires: Comparison, validity and generalization

There are six purpose-built Reinforcement Sensitivity Theory (RST) personality questionnaires currently in use to measure the fight-flight-freeze system (FFFS), the behavioural inhibition system (BIS), and the behavioural approach system (BAS). They differ in their conceptualizations and operational constructs, and this poses a problem for their differential validity and the generalizability of results, and comparison of results from different studies. This paper examined the psychometric properties of five of these RST questionnaires, with a total sample of 821 participants, taken from the factor structures for the Croatian translations of BIS/BAS scales, SPSRQ, Jackson-5, RSQ and RST-PQ. Data were analysed by correlational and confirmatory factor analyses. We found some of these questionnaires achieved marginal to adequate fit indices, and they showed ambiguity in terms of convergent validity for all three general behavioural systems. These findings highlight the difficulties with generalization and comparison of results with the use of different RST questionnaires. Based on these findings, as well as the ongoing debate concerning how best to measure RST constructs, we provide information on how to interpret results from the studies conducted with different RST scales.