Myers-Briggs Type Indicator:
Basics of the MBTI System
The Myers-Briggs Type Indicator or MBTI were developed during World War II by Katharine Cook Briggs and Isabel Briggs Myers. They divided people up into 16 personality type groups. Note that these groups are not evenly distributed across people. For example 12% of people are ESFJ but only 1.5% of people are INFJ.