Implicit and explicit attitudes in transportation research: A literature review

Dual-Process Models of Attitudes (DPMA) have provided new concepts and methods for attitude-behavior research in the field of transportation. Notwithstanding, there is a lack of critical reviews on this topic; leaving researchers with an unclear picture of the key issues to consider in developing new research. This paper reviews previous studies on DPMA in traffic and transportation research. A systematic review of English and non English language articles using Transport Research International Documentation (TRID) as main database was conducted. Additional studies were identified by searching in ScienceDirect and Google Scholar. A total of 1674 references were revised. Twenty-eight articles met the inclusion criteria. Four central issues were examined: (a) the role of implicit and explicit attitudes in transport behavior, (b) the degree of relationship between implicit and explicit attitudes, (c) the types of measures used to assess implicit attitudes, and (d) the malleability of implicit attitudes. The review has identified that: (a) implicit attitudes were associated with a wide variety of transport-related behavior, (b) implicit and explicit attitudes were weakly correlated (mean correlation, weighted by sample size was r = 0.11), and little knowledge exists on factors moderating the implicit-explicit relationship, (c) the evidence on the indirect measures' better resistance to social desirability bias as compared with traditional techniques is scant and inconclusive, (d) some studies exhibit problems in the application of indirect measures, and (e) few studies (n = 2) aimed to evaluate interventions for attitude change. The analysis showed the sustained growth of the applications, the potential of DPMA, and the need for more rigorous research. Most studies of area do not consider the theoretical and methodological shortcomings of the DPMA, and tend to be based on a controversial notion of implicit and explicit attitudes. (c) 2020 Elsevier Ltd. All rights reserved.