The story
From the metaphor in which a pot of crabs, one crab attempts to escape over the side, but is relentlessly pulled down by the others in the pot.
Etymology from Wiktionary, CC BY-SA 4.0.
crab mentality
Today it means: A phenomenon in which a person or a group of people attempt to hinder the progress or success of others, even if such success does not directly affect their own well-being. Full definition →