I’m Katharine Cook Briggs and I'm Isabel Briggs Myers. I, the Mum, began my research into personality in 1917. I recognized that Jung's theory was similar to, but went far beyond, my own. My four types were later identified as corresponding to the IXXXs, EXXPs, EXTJs and EXFJs.
I, the Daughter, joined my mother's research and I progressively took it over entirely.