My family does this, I remember watching them try to crawl out of the pot for the first few minutes so it's not true

I was around as a kid when my aunt boiled some crayfish alive. The way they run in the pot and the sound they make still haunts me to this day whenever I see these little animals. I don't need science to tell me if something feels pain or not when being boiled alive...

I have boiled a lot of lobster and crab live. In my experience, they stop twitching in 5 seconds or so. I find this method faster more humane than chopping through their carapace and rooting around their head with a knife looking to scramble their brain while they struggle.

The latter is not a task I expect many home cooks to be good at.

They key is to have the water at a rolling boil and have enough volume that it doesn't cool when you add a 2 lb lobster head first.

I suspect a lot of the horror stories are from people who added lobster to a pot with too little water.