The concept of intersubjectivity has experienced a remarkable growth in psychoanalysis worldwide but especially in North America, touching almost every school and grouping. In this chapter I focus on the history of this development and some of the ways it has been understood by different authors. I began by searching the PEP archive for examples of the term “intersubjectivity” in psycho analytic journals and was surprised to find how much its use has boomed. Between 1940 to 1960, I could find the term only in two citations; over the next twenty years to 1980, it occurred 17 times; but from 1980 to 2000 there were 974 references; then 1,915 times between 2000 and 2014. Of course, the word gets applied in many ways with multiple interpretations of its meaning. Despite this confusion of tongues, however, “intersubjectivity” has become a kind of shibboleth for contemporary psychoanalysis. Why did this term become so central for different analytic schools and what conclusions might we draw from its prevalence?