News coverage of the 2024 election season has often centered on how partisan division has affected our politics. But a new analysis shows that political polarization also poses significant health risks-;by obstructing the implementation of legislation and policies aimed at keeping Americans healthy, by discouraging individual action to address health needs, such as getting a flu shot, and by boosting the spread of misinformation that can reduce trust in health professionals. 

“Compared to other high-income countries, the United States has a disadvantage when it comes to the health of its citizens,” says Jay Van Bavel, a professor in New York University’s Department of Psychology and an author of the analysis, which appears in the journal Nature Medicine. “America’s growing political polarization is only exacerbating this shortcoming.”

But despite the challenges of political polarization, the analysis, which considered more than 100 experimental papers and reviews, pointed to potential ways to both minimize its impact on Americans’ health and promote health-care practices.

Division is a major problem and the one real solution is trust. Public health agencies need to work with trusted voices and leaders, being proactive at sharing information, engaging questions, and not writing off concerns as irrelevant. In a time when some people look less to doctors and more to prominent figures for information on decisions related to our health, the best steps involve engaging directly with those voices.” 

Kai Ruggeri, professor at Columbia University’s Mailman School of Public Health and one of the paper’s authors

The analysis, which also included Eric Knowles, a professor in NYU’s Department of Psychology, and Shana Kushner Gadarian, a professor in Syracuse University’s Department of Political Science, considered Americans’ views of the opposite party over four decades, health-related behaviors during the coronavirus pandemic, and comparative data from other countries.

Over the past four decades, the paper’s authors note, partisan animosity has steadily increased in the US. By 2020, Americans were much more likely to say they “hate” the opposite party than they were to say they “love” their own party; by contrast, from 1980 through 2008, Americans were more likely to say they loved their own party than they were to say they hated the opposite party-;though “party love” relative to “opposite party hate” has drawn closer virtually every year since 1980, becoming approximately even in 2012 and with “hate” surpassing “love” beginning in 2016. 

In their analysis and review of previous studies, the paper’s authors also examined a range of health-care related studies, which showed the following:

• As individuals move further from the political center-;in either direction-;there is a deterioration in individual and public health, such as trust in medical expertise, participation in healthy behaviors, and preventive practices, ranging from healthy diets to vaccination. Notably, individuals who are more ideologically extreme than their state’s average voter have worse physical and mental health.
• Polarization affects what health information people are willing to believe and shapes the relevant actions they are willing to take. This may mean disregarding accurate information or believing misinformation-;depending on whether or not it comes from sources they are aligned with or disagree with.
• Political leaders, inside and outside the US, may make public health worse by linking health behavior to partisan identity rather than medical needs or expert advice, thereby undercutting the role of expertise and ignoring approaches grounded in science, often leading to attacks on medical professionals and the healthcare system.
• Republicans were less likely to enroll in marketplace insurance plans through the Patient Protection and Affordable Care Act (“Obamacare”) than were Democrats after most of its provisions took effect a decade ago. These differences have been linked to excess sick days from work, higher healthcare premiums, and higher mortality rates.
• As policy polarization at the state level has increased over time, so has the difference in lifespan and health across states-;Americans who live in states with more progressive social policies, such as generous Medicaid coverage, higher taxes on cigarettes, more economic support (e.g., a higher minimum wage), and more firearm regulations live longer than their counterparts in states that embrace more conservative policies. 
• After the Trump administration and other Republican leaders expressed skepticism regarding COVID-19 prevention behaviors, partisan elites and news sources amplified this belief and polarized Republicans readily accepted it: large gaps in distancing and then vaccination rates between Republicans and Democrats widened during the pandemic, even as evidence mounted about the risks.
• These differences were not limited to the US: a previous study of 23 European countries found that national levels of partisan polarization accounted for nearly 39% of the variation in vaccination levels.
• Notably, another study of 67 countries found almost no correlation at all between left/right political ideology and support for public health recommendations, suggesting that polarization, rather than political ideology, was the greater risk factor to their citizens’ health.

The authors write that “although polarization is a risk factor for disease and mortality in a public health crisis, this outcome is not inevitable.” They point to a study comparing the US and Canada that suggests policy and leadership decisions can mitigate the potential harm from polarization. Although both nations were politically polarized at the onset of the pandemic, research found that political leaders in Canada took a different approach to those in the United States and also experienced a significantly lower level of illness and mortality. 

This and other studies point to specific approaches public officials and health-care professionals can take, which the Nature Medicine authors outline:

• Highlight shared identities between public health officials and target populations-;these can include shared partisan identities, nonpartisan identities, or national identities. 
• Communicate information about how many people are following public health guidelines-;instead of focusing on people who are failing to follow it.
• Use trusted civic leaders-;such as religious, athletic, and military spokespersons-;to expand and supplement health messages from local and national leaders and reach diverse communities.
• Debunk misleading or false information using fact checks, pre-bunking, and other validated strategies 

“Polarization is not only an American concern, but one that is increasing in many countries,” says Syracuse’s Gadarian. “This means we should be investing more in understanding and diminishing its impact on public health by encouraging collaborations between medical professionals and social scientists.”