I guess the word "useless" is a somewhat harsh and subjective term, although the term: "useless college degres" yields lists from many reputable sources. Studying anything will yield some benefit for sure. It is certainly better than sitting around doing nothing. Earnings potential may be a better gauge for some.
Worst-paying college majors
Top ten by median salary within five years of graduation
Four majors — family and consumer sciences, the performing arts, general social sciences and social services — actually pay less than the median salary of $35,805 for full-time workers in the U.S., regardless of education, according to the Federal Reserve Bank of St. Louis.