Here’s one more thing for liberals and conservatives to argue about: who lives longer. In a new study published in the Journal of Epidemiology & Community Health, researchers state that liberals live longer than conservatives, basing their results on individual death records, which is a “more valid measure” than self-reporting on health and community death rates.

“We were surprised [about the results],” Roman Pabayo, a community health researcher at the University of Nevada, Reno, and an author of the study, told USA Today. That’s because past research has actually found that conservatives, on an individual level, are happier than their liberal counterparts. And overall wellbeing and happiness is generally linked to healthier, longer lives.

Of course, it’s complicated. One recent study found that conservatives are personally happier than liberals, but people who live in liberal countries are happier on average than those who live in less liberal countries.

“Liberal governments tend to do more to shield citizens against certain hardships, such as unemployment and poverty, which can make people feel happier overall,” said Adam Okulicz-Kozaryn, lead author of the happiness study, in a press release. “On the other hand, conservatives rate their wellbeing higher than liberals because conservatives more readily support and rationalize the status quo, thus, believing that socioeconomic hardships are a result of individual shortcomings.”

So what’s making liberals live longer if they’re not necessarily happier on a personal level? No one really has the answers. It could have something to do with lifestyle, habits, or “how you look at life, [and] how you react to adversity,” Pabayo told USA Today. “We need to figure out what’s really going on.”

Other researchers who weren't part of the study argue that the mortality differences are quite small, and the data is inconsistent with other research. They also state that Republicans and conservatives are more likely to be religious and involved in social networks like church communities — as well as less likely to smoke — all of which has been tied to healthier, longer lives. Thus, the new study’s results are seemingly contradictory with past research.

The study examined over 32,000 adults who identified themselves as either Democrats, Republicans, independents, or other. They were also asked to choose between defining themselves as liberal, moderate, or conservative. The authors of the study tracked who died over the course of 15 years. They found that conservatives and moderates were six percent more likely to die during the follow-up than liberals who matched them in age, sex, and even socioeconomic status. Interestingly, however, the authors found that when comparing between party lines, there was no difference in death rates between Democrats and Republicans.

An accurate study of who lives longer and what causes it would be quite difficult to carry through. So until then, the contest of life span will have to remain a contentious topic. Political Satirist Daniel Kurtzman, however, believes the study is true. “Did they really need a study?” he told USA Today. “Conservatives like guns, tobacco, fossil fuels, deep-friend endangered caribou,” while liberals “like yoga, weed, clean air, free-range kale… and giving everyone free health care.”

Source: Pabayo R, Kawachi I, Muennig P. Political party affiliation, political ideology and mortality. Journal of Epidemiology & Community Health. 2015.