"Spiralling" socks

When I knit socks on DPNs, they always seem to “spiral” as they come off the needles. In other words, they don’t hang straight down as they get longer, but rather the whole tube twists a bit. What causes this?

Are you knitting through the back of the loop? In other words, are you inserting the needle over the right side of the loop and scooping the yarn through? If so, that’s the problem. It’s a twisted stitch, and doing that twisted stitch in the round causes the knitting to spiral.