This question already has an answer here:
I've read the comparison between APS-C and Full Format at
The depth of field is controlled by the circle of confusion, which is the area of which light is spread when hitting the image plane. It gets "blurry" once the circle of confusion is bigger than the pixel size.
Now for a Full Format camera the pixels are significantly bigger compared to an APS-C camera (for example D7100 - 3.9um per pixel vs. D600 - around 6um per pixel), so given the same lenses (as in the linked question), I thought the DOF should be shallower for the APS-C instead, since the smaller pixel size allows only a smaller circle of confusion.
So why is it stated differently in the other question?