Pro-life activists try to block the signs of pro-choice activists in front of the the U.S. Supreme Court during the 2018 March for Life on January 19th, 2018, in Washington, D.C. (Photo: Alex Wong/Getty Images)

It may be the last thing we need, given our intense political polarization, but America is about to re-open the debate over abortion. Once new justice Brett Kavanaugh is confirmed, the Supreme Court is likely to further restrict a woman's right to terminate her pregnancy, very possibly allowing individual states to ban the procedure altogether. That will throw the issue squarely back into the political realm.

What psychological predispositions, ideological assumptions, and ethical values lead one to support, or oppose, abortion rights? Perhaps anticipating this moment, psychology researchers have been exploring this question in recent years, and they have come up with some nuanced answers.

Yes, anti-choice attitudes are linked to both sexist beliefs and religious faith—but those blanket observations obscure important details.

For example, one large study found anti-abortion views are associated with fundamentalism, rather than religiosity per se. And another found the benevolent form of sexism—that is, the impulse to put women on a pedestal—is a stronger predictor of opposition to abortion than the overt, hostile variety.

"The idealization of women—and motherhood in particular—comes at a substantial cost," a research team led by Yanshu Huang of the University of Auckland wrote in a revealing 2016 study. "Namely, the restriction of women's reproductive rights."

Let's work our way toward that conclusion by starting with a couple of well-known traits that are aligned with abortion antagonism: political conservatism and religious faith. In a 2017 study, Steven Yen and Ernest Zampelli analyzed data on nearly 5,000 Americans who completed the General Social Survey between 2006 and 2014.

Respondents were asked their level of support or opposition to abortion in a variety of circumstances, some strictly elective ("She is married and does not want any more children"), others based on traumatic circumstances ("She became pregnant as a result of rape").

They also reported their political ideology, and two measures of religious faith: "religiosity," which was based how often they attend services and privately pray, and "religious orthodoxy," measured by the fundamentalism of their denomination and their belief in the literal truth of the Bible.

Perhaps surprisingly, Yen and Zampelli found increased religiosity—that is, taking your faith seriously, and acting accordingly—actually increased support for abortion rights. In contrast, religious orthodoxy, a.k.a. adherence to hard-line tenets, was strongly associated with opposition to abortion.

This suggests pro-choice advocates shouldn't rule out the religious as a source of support. The key factor isn't the strength of your faith, but the dogma of your particular church.

Turning to ideology, the researchers found that—to an even greater extent than they expected—the more conservative people professed to be, the more likely they were to support abortion restrictions. They attribute this to George Lakoff's "Strict Father Model" of morality, in which the patriarch is seen as "the family's moral authority and protector."

According to this mindset, which is strongly linked with social conservatism, "sex is reserved for marriage, and must always be open to procreation," they write. "The planning/timing of births devalues children, and is consequently immoral."

Of course, some would simply call that attitude sexist. But in psychological terms, sexism is commonly divided into two types: hostile, which displays overt antipathy toward women, and benevolent, a.k.a. protective paternalism.

On a standard questionnaire, hostile sexism is measured by responses to statements such as "Women are too easily offended," "Women seek special favors under guise of equality," and "Women seek power by gaining control over men." More subtle benevolent sexism is measured by responses to a different set of assertions, including "A good woman should be set on a pedestal" and "Women have a quality of purity few men possess."

In a 2014 study of 627 Americans, and a 2016 study of more than 6,800 New Zealanders, both varieties of sexism were strongly associated with opposition to abortion. In the latter sample, "30 percent of the left-right difference in abortion stance was explained by sexism," according to researchers Gordon Hodson and Cara MacInnis.

But Yanshu Huang's aforementioned study found the type of sexism mattered considerably. Analyzing data on more than 6,800 New Zealanders who filled out surveys in 2011 and again in 2012, the researchers found benevolent sexism, but not the hostile variety, was linked to negative attitudes toward abortion one year later. This association held even after taking into account participants' gender, religious identification, and political orientation.

To learn more, the researchers conducted a follow-up study featuring 309 undergraduate psychology students (three-quarters of whom were women). Like members of the larger study, they filled out questionnaires measuring sexism and describing their attitudes toward abortion.

In addition, they responded to seven statements designed to reflect their attitudes toward motherhood. These included "A woman is not a 'real woman' until she becomes a mother" and "A woman who doesn't want children is unnatural." (They expressed their level of agreement or disagreement with each on a one-to-seven scale.)

The researchers found sexism "was uniquely positively associated with beliefs about the importance of motherhood for women. In turn, beliefs about the importance of motherhood were negatively associated with support for abortion."

This suggests that if you view motherhood as the pre-ordained role of women, having an abortion is, in effect, defying the natural order—or, if you are religious, the law of God.

A larger study, conducted in the United States and/or other major nations, will be needed to confirm these results. But it's hard to argue with the researchers' conclusion that they "reflect the inherently political nature of gender-role attitudes, and, perhaps more importantly, how the idealization of motherhood ultimately undermines women's rights."

For many, it seems, the belief women should be "cherished and protected" effectively means they should be freed from the bother of making their own decisions—especially regarding abortion.