The diachronic relationship between demonstratives and first/second person pronouns

It is well known that demonstratives are the cross-linguistically common source of third person pronouns due to the functional similarity between them. For this reason, they are morphologically related to or formally indistinguishable from one another in many languages. First and second person pronouns, on the other hand, typically have historical sources other than demonstratives. However, unlike the close relationship between demonstratives and third person pronouns, the fact that demonstratives and first/second person pronouns have a very tenuous diachronic relationship has not attracted much attention in previous studies. Based primarily on historical data from Japanese, the present study shows that there are at least three functional reasons why demonstratives do not usually give rise to first/second person pronouns. This study also discusses a limited context in which a demonstrative does develop into a second person pronoun.