I see your point. I’m good at learning languages, and 100 hours of self-study would make me sound “fluent” to most Americans. That said, I would self-rate myse

I see your point. I’m good at learning languages, and 100 hours of self-study would make me sound “fluent” to most Americans. That said, I would self-rate myself as “minimally proficient, mostly at short simple conversations”. > Maybe the study clarifies this They do: “The mean self-reported proficiency for the highest-proficiency language was 20 out of the maximum score of 20 (SD = 0; note that for three participants, the highest-proficiency language was not their native language; Table S1), 18.3 for the second most proficient language (SD = 2.45, range: 10–20), 15.8 for the third most proficient language (SD = 3.36, range: 8–20), 13.3 for the fourth most proficient language (SD = 4.034, range: 7–20), 11.2 for the fifth most proficient language (SD = 4.23, range: 4–20), and—for individuals with proficiency in more than five languages—10.33 for the sixth most proficient language (SD = 3.99, range: 4–18).” These were folks who self-reported (perhaps inaccurately, but still…) at a relatively high level of proficiency.