The most likely cultural trait responsible for the difference in workweek length between the U.S. and the Netherlands in 2020 is:
**The U.S. culture prioritizes capitalism, while the Netherlands’ culture prioritizes health and welfare.**
This response highlights the contrasting values associated with work and life balance in the two countries, where the U.S. tends to emphasize work and economic productivity more, while the Netherlands places a higher value on well-being and quality of life.