The Briggs-Myers Personality Test is an MBTI assessment that divides individuals into different personality types based on their predominant mental functions, such as extraversion, introversion, sensing, judging, and perceiving. While personality type does not guarantee success in Forex trading, profitable traders tend to be those who think critically, analyze situations, and make quick decisions – attributes commonly associated with the INTJ personality type, which favors logical reasoning and pattern recognition in problem-solving.