Yes, they do.
Same plug, same wiring, different protocol.
PS/2 uses a different plug, different wiring, and the same protocol as AT (although, IIRC, they're supposed to use a different code page for something. Nobody did that. Not even IBM, who said that they were supposed to. (Otherwise, a pre-PS/2 Model M wouldn't work properly on a newer machine, nor would a PS/2 Model M work properly on an AT.))