This stereotype may have some basis in reality — Americans work an average of 47 hours a week, one of the highest figures in the world.
Meanwhile, in many European countries, the average is below 40 hours a week, and in Germany and Sweden, it's closer to 35. On top of the crazy hours, the United States is the only developed country in the world that doesn't guarantee any paid vacation for its workers. And what little paid leave American employees get, they often feel pressured not to take full advantage of.
Given that reality, it's no surprise Americans have developed a reputation abroad for being slaves to their work.