The more college students drink, the lower their grade point average. That’s the finding of a new survey of almost 14,000 college students. Time spent drinking was second only to time spent studying outside of class as the most reliable predictor of a student’s GPA, the survey found.

The survey, reported by The Daily Beast, included about 13,900 incoming freshman at 167 colleges. It was presented last week at the American College Personnel Association conference by Todd Wyatt of George Mason University.

When drinking was accompanied by other activities such as volunteering or other extracurricular activity, the researchers found fewer negative consequences such as missing class or work or failing assignments, compared with classmates who drank but didn’t participate in outside activities.

The researchers were surprised to find that unlike drinking, spending time online on social networking sites such as Facebook had little effect on grades.