In "A New Hope", Vader brings an interrogation droid into the cell with him when he's interrogating Leia. He has, at that point, no reason to suspect that Leia is Force-sensitive, which could be construed to lend credence to the theory that physical/psychological torture makes Force mind probing easier (or maybe he's just a sadist, that's also a valid theory).
Also of note: Vader is disgruntled when Leia is able to resist his mind probe, but he doesn't conclude from this that she's FS.
Later in the trilogy, though, both Vader and Palpatine are able to pick up Luke's thoughts pretty readily. Maybe Luke is less mentally disciplined / more emotive than Leia, or maybe being an active Force-user makes him "louder"/easier to read?
Tangentially relevant: a variety of alien species (Hutts, Toydarians, Epicanthix etc) are innately difficult/impossible to mind trick/probe, Because Reasons.
TL;DR: imo, strong canonical support for 'torture makes mind probe easier' and 'ability to resist probe varies between people, not a reliable sign of Force-sensitivity'.
Re: Question about Poe's interrogation
Also of note: Vader is disgruntled when Leia is able to resist his mind probe, but he doesn't conclude from this that she's FS.
Later in the trilogy, though, both Vader and Palpatine are able to pick up Luke's thoughts pretty readily. Maybe Luke is less mentally disciplined / more emotive than Leia, or maybe being an active Force-user makes him "louder"/easier to read?
Tangentially relevant: a variety of alien species (Hutts, Toydarians, Epicanthix etc) are innately difficult/impossible to mind trick/probe, Because Reasons.
TL;DR: imo, strong canonical support for 'torture makes mind probe easier' and 'ability to resist probe varies between people, not a reliable sign of Force-sensitivity'.