Well, if you add up the number of speakers of second languages according to this page, and assume anybody speaks at least one language as their first one, you’ll end up with almost exactly 1.4 as the average number of languages any given human speaks.
That’s the lower bound, though, as I only added up second languages where the number of speakers is at least one million, and Wikipedia doesn’t list many more anyway.
Well, if you add up the number of speakers of second languages according to this page, and assume anybody speaks at least one language as their first one, you’ll end up with almost exactly 1.4 as the average number of languages any given human speaks.
That’s the lower bound, though, as I only added up second languages where the number of speakers is at least one million, and Wikipedia doesn’t list many more anyway.