DESCRIPTION
You question the target, backed up by the threat of magical pain. You may ask one question per two caster levels. The target can either answer the question or take 1d4 points of damage plus your Wisdom bonus. The target is not compelled to answer truthfully, but the threat of pain gives it a –4 penalty on Bluff checks to convince you when it is lying.
that's the description is that a goof? its saying wisdom for wizards or is it intelligence for them and they typo
http://paizo.com/pathfinderRPG/prd/ultimateMagic/spells/interrogation.html
^ link for spell
I think it's Wisdom because that's what's used for Bluff/Sense Motive. Note that the target only takes damage if it does not answer. If it answers truthfully, nothing happens. If it answers falsely, it has a -4 to its bluff check.