TITLE: Interpretability and consistency strength
QUESTION [7 upvotes]: I have heard there is some fairly recent result showing that whenever theories $T$ and $T'$ have the same consistency strength, then each can interpret the other.  I suppose it refers to first order theories, and I do not know exactly what kind of interpretability it uses or what measure of consistency strength.
Can anyone give me the result, or point me in a good direction?

REPLY [3 votes]: John Steel spoke at the EFI series at Harvard concerning his ideas on The triple helix, which has to do in part with the interplay of large cardinal strength and the arithmetic interpretability hierarchy. This is not exactly the claim you mention, but there is a family resemblance.