Context: Although software development is an inherently human activity, research in Software Engineering (SE) has focused mostly on processes and tools, thus failing to recall the human factors behind it. Even when explored, researchers typically do not properly use the psychological background to understand better human factors in SE, such as the psychometric instruments, which aim to measure human factors. Objective: Our goal is to present an overview and reflections on psychometric instruments in SE research regarding personality. Method: We conducted a systematic mapping of the literature to generate a catalog of the psychometric instruments used. Results: This dissertation contributes with an update of an existing secondary study to cover fifty years of SE research (1970 to 2020). We observed remaining discrepancies between one of the most popular adoption instruments (MBTI) and existing recommendations in the literature on the use of this instrument. Conclusion: The findings lead us to conclude that the adoption of psychometric instruments regarding personality in SE needs to be improved. Future work directs us to analyze the mapped literature under the lens of social science specialists and researchers.