Internal Monologue

In which Rat isn't sure

This claim has been floated around the internets a lot, see e.g. Here's What It's Like To Not Have An Internal Monologue.

As far as I can tell, in most cases it can be traced back to this study:

Ren X, Wang T, Jarrold C. Individual Differences in Frequency of Inner Speech: Differential Relations with Cognitive and Non-cognitive Factors. Front Psychol. 2016 Nov 2;7:1675. doi: 10.3389/fpsyg.2016.01675. PMID: 27853439; PMCID: PMC5089968.

What however is usually left out is… it’s a Chinese study. Surely using an ideographic/logographic writing system does affect the way one thinks, and wording of surveys has an impact, too. Hence I’d be cautious about extrapolating it to the whole humankind.