The phrase comes from the way crabs actually act in a bucket or basket. When I was a child, my family occasionally visited North Carolina, where my mother was raised. Her mother, two brothers, and a sister resided in that state. On one particular trip we visited my uncle Johnny, who was an avid fisherman and hunter. His freezer was always full of wild game, fish, and seafood that he had caught or killed himself. On this trip, we went with him to the inland waterways of NC, got in his rowboat, and went out to the oyster bars and areas where crabs were plentiful. There are laws against harvesting these crustaceans in many locations now, but back then it was common practice for the locals. We had a couple of bushel baskets in the boat. One was for the oysters, and one for the crabs we would catch. It was fairly easy to catch the crabs. We would simply lower a line into the water where they lived that had something attached to it that the crabs could latch onto. It didn't really matter what that object was, as long as it would sink. A crab or two would grab onto the object, and we could pull it up to near the surface, where the crabs would drop off, but before they let go, we scooped them out of the water with a kind of net. Then my uncle or dad would carefully dislodge the crabs from the net and place them into the basket.
I remember asking, "Can't they climb out?"
My dad chuckled a little and said, "They'll keep each other in there."
I watched in fascination as one crab would begin to crawl up the side and two or three others would grab it and pull it back down.
Now I understand what my dad said, and where the phrase comes from - crab bucket syndrome.
After returning to my uncle's house, huge pots of water were placed on the stove to boil. The crabs were lowered into one pot, and the oysters were placed in a steamer basket in the other. I learned to love shellfish, which I still enjoy, but infrequently these days.
