You can blame that third cup of Joe on your genes

the volume -- and frequency -- of a person's daily coffee consumption

The research was led by Marilyn Cornelis of the Harvard School of Public Health, and published on Tuesday by the journal Molecular Psychiatry.

"Overall, we have known for a long time that there are some genetic components for our coffee-consuming behaviors," Cornelis told CNN

Researchers were able to identify six regions in human DNA that were not previously linked to coffee-drinking behavior, which could explain why one drinker will lie awake at night twitching after one cup while another can gulp down the whole pot before their REM cycle.

The study analyzed data from several studies that polled more than 120,000 people on how much coffee they drink a day, then scanned their DNA.

Cornelis said researchers will be able to use these genetic variants to study the health effects of coffee -- and caffeine -- better.

"Most (human) population studies of coffee and heath assume everyone responds to a given amount of coffee in the same way," she said. "We know that isn't true and we now have specific genetic variants that we can apply to our studies which will enable us to generate better results."

According to the National Coffee Association's 2014 drinking trends study, 61% of American adults consume coffee on a daily basis.

CNN