Why is its possessive form without an apostrophe, when it’s opposite of other English rules and often counter-intuitive?

Question

See this headline: proper usage, but difficult to parse. “It’s” = “it is”, exclusively. The origin of this “exception” rule?

In: 6

Answer 1

Historically, “it’s” was used as both the possessive *and* the contraction. But this lends itself to confusion and the lack of apostrophe in other personal pronouns (yours, theirs, his, hers, etc.) meant that the apostrophe was dropped for the possessive form of its and retained for the contraction.