Families generally offer homogenous groupings when it comes to politics — but there's always that outlier brother-in-law or great-aunt.
The last time Kathy Neal's family had a big gathering, they got into a fight about politics.
At her niece's high school graduation in May, the conversation turned to gas prices, which led Neal to argue that oil companies were not just profiteering at the expense of consumers, but getting billions in government subsidies to boot.
Her brother strongly disagreed, contending that EPA regulations are strangling oil companies and limiting their profits to a nickel a gallon. "He challenged me and said, 'What are your sources?' " recalls Neal, who works as a cashier in Clayton, Mo.
A high school graduation may seem an odd time for bickering about energy policy. But American politics have grown so polarized that it's difficult to turn the arguments off, even at family gatherings.
With Thanksgiving coming just weeks after a contentious election, there are bound to be similar debates at many tables.
One Democratic friend emailed me to say his family has gotten pretty good about not ganging up on his brother-in-law, the lone Mitt Romney supporter in the bunch, "but it's gonna be hard not to gloat a LITTLE."
Maybe the reason is that because we don't pick our families, they present a rare opportunity in contemporary life to have a close encounter with someone who doesn't share our political values.
It's "very rare" to spend much time around people who have different partisan leanings, says Diana Mutz, a University of Pennsylvania political scientist and author of Hearing the Other Side, a book about political interactions.
Outside of work, which affords no choice, people largely opt to associate with others who share their leanings, Mutz says. They may not always be conscious of political differences at first, but they pick up on cues about whether they generally agree or disagree with those around them.
Think about your own Facebook or Twitter feeds. Do you put up with a lot of people who disagree with you?
"The more interested in politics you are, the more homogenous your network is," Mutz says. "People sort themselves out into homogenous groups, even when that group is about gardening or bowling."
In terms of politics, families generally offer homogenous groupings themselves. When both parents share partisan leanings, they pass those on to their children about 75 percent of the time, some political scientists estimate.
Still, many families seem to have those outliers — the brother-in-law or great-aunt who annoyingly forwards talking points all year from, say, radio host Rush Limbaugh or MSNBC's Rachel Maddow. Thanksgiving offers the recipients an opportunity finally to prove them wrong.
"I have that same kind of conflict with my family," Mutz says. "We all want to believe that if we had the same information, we would all agree, and that's not the case."
Family gatherings can offer the chance to debate politics without immediately "demonizing" those with different views as "zealots" or "bad humans," says Robert Baron, a University of Iowa psychologist who has studied political polarization.
"We have a strong tendency to question their motives and how well-informed our political enemies are," Baron says. "I actually think if you have a beloved uncle and you're at Thanksgiving and you respect him as an intelligent person, you're much more likely to have a positive discussion than not."
Baron says he and his own uncle used to go at it during the 1960s over matters such as the Vietnam War and the sexual revolution. He recalls that his uncle, after the meal was over, would invariably throw an arm over his shoulder and say, "You know I still love you."
Still, Baron says, "People who have any brains just avoid the topic if they know they've got a couple of family members who don't share the same point of view."
But avoiding ganging up on Uncle Frank can be difficult, if he insists on pressing his point about same-sex marriage or President Obama's alleged socialism.
"The polarized culture is right there on the fringes," says Kirk Cassels, a social media specialist at Dartmouth College in New Hampshire. "If there's a trigger — whether everybody's tired or they've had too much to drink or the sheer number of people or the travel — people can certainly come to a point where politics could push them over the edge."
Cassels says he's never been in a situation where politics ruined a family dinner, but he has plenty of friends who report being infuriated by an in-law spouting off about either conservative or liberal politics.
To avoid argument, it might be best to follow pub rules and old-fashioned etiquette, and leave off talking about politics and religion altogether. Neal, the cashier from Clayton, says she and her brother are going to "keep it low" on Thanksgiving and "agree to disagree."
"If you plan to argue about politics & election during the upcoming turkey holiday, let me share this w/ you now: YOU'VE RUINED THANKSGIVING!" Cassels tweeted the other day.
It's going to be hard for many to resist making their case. It's not every day that contemporary Americans have the chance to try to persuade people who don't already share their politics.
Kara Heideman, who works in education in Lincoln, Neb., says her family doesn't fight about politics, but she regrets not pressing her point of view more strongly during what proved to be a close presidential election.
"I will say that I do wish I had done a better job explaining why I support Mitt Romney and the Republican Party to my relatives," she says. "Most of them live in a swing state — Iowa — and every little bit helps."