Background: Type D personality is one of the personality types that makes people prone to physical and psychological diseases and can be related to cognitive factors including cognitive bias. Howevere, there is a research gap about biases specific to this personality type.
Aim: Considering the existing research gap in this field, the present research was conducted with the aim of designing and validating the type D personality cognitive bias modification intervention and its effect on the two components of this type.
Methodology: The current research was carried out in a pragmatism paradigm with a mixed method in two parts, qualitative and quantitative. The target population included the students of Persian Gulf University in Bushehr, and in order to implement the qualitative part, a semi-in-depth interview was conducted with 21 students with type D personality by purposive sampling method. Then, 277 people were selected with the multi-stage cluster sampling method and the cognitive biases questionnaire was distributed among them for validation. Then, based on the remaining cognitive biases from the validation, a software for the Android operating system was designed to modify cognitive biases in the form of scenarios, and 84 people in two groups of 42 people, experiment and control, responded to it. Qualitative data analysis was done using MAXQDA2020 software and quantitative data analysis was done using SPSS26.
Results: In the qualitative section, 56 initial codes were placed in the two main themes of personal bias and environmental bias, each of which had other subthemes and were included in the axial code of interpretation bias. Then, 56 items were reduced to 52 items after checking content validity. During the exploratory factor analysis, 11 components with 31 items, but in the confirmatory factor analysis, 6 components with 20 items remained as the type D personality interpretation bias questionnaire. Then, based on the items related to type D, the scenarios o