Well anti-anxiety compression vests work for cats and dogs and there's some very preliminary evidence that deep pressure touch improves subjective relaxation https://www.ncbi.nlm.nih.gov/pubmed/3688151/

This is actually the first time I've ever heard of weighed blankets. As someone with severe anxiety that's helped with a hard squeeze, I'm very interested in getting one, I just wish I could try one first.

> work for cats and dogs That could still be conditioning.

> deep pressure touch improves subjective relaxation That could still be conditioning.

I'm not saying it definitely is conditioning, but I don't see enough evidence to rule it out.

For example, these animals could associate the pressure with the warmth and comfort of being the in the womb. So in a way they've been conditioned by being in the womb. Maybe animals grown in a 'test tube' wouldn't give the same results.