Google gave me mostly AI slop and pop psychology, but this article is an in-depth summary of the literature on the topic of inner speech, for anyone interested (and dedicated - it’s long and very technical).
It doesn’t seem to justify dichotomizing people into those who “have it” and those who don’t. Research looks mostly focused on what cognitive or developmental purpose it serves.
Inner speech can be defined as the subjective experience of language in the absence of overt and audible articulation. This definition is necessarily simplistic: as the following will demonstrate, experiences of this kind vary widely in their phenomenology, their addressivity to others, their relation to the self, and their similarity to external speech.
So, it’s on a spectrum, highly subjective, and difficult to talk about with precision.
I personally do not normally think in words, but I certainly rehearse/relive conversations. I also complain to myself with words when I am really miserable, I think it’s comforting to “say it out loud” (inside). Do I have an inner monologue?
Epstein famously received an unprecedented federal non-prosecution plea deal in 2008. There were dozens of victims who had come forward in those charges, but they (along with anyone else who hadn’t come forward) were instantly disenfranchised by that deal. The prosecutor who arranged that plea deal was Alex Acosta (who went on to serve as Labor Secretary under Trump 45 🤔).