The family was posited by Stephen Wurm as a branch of his 1975 Trans–New Guinea proposal.

None of the families are closely related; indeed, it is difficult to demonstrate a link between any of them.

The remainder of the family, which he calls South-Central Papuan, is only tentatively retained: their pronouns are suggestive of a relationship, but this has not been demonstrated.

Evans (2012), for example, argues that the inclusion of the Yam language at least is not justified on present evidence.

[1] Languages within the Southern New Guinea linguistic area generally share these typological features.