Shaped charges and torpedo warheads developed in parallel

Did shaped-charge technology move from another weapon family into torpedoes, or develop the other way around?

It was broadly parallel development rather than a simple one-way transfer.

Shaped charges in other weapons and torpedo warheads do not have a simple line of descent in this account. Shaped-charge work was already under study in more than one field. The relationship was therefore broadly parallel development. Simultaneous technical experimentation should not be turned into a false single-origin story.