Purity is an unusual foundation, since it can apply at the object level or the meta level. On the object level, people believe things like “don’t eat pork because it’s unclean” or “don’t have premarital sex because it takes away your purity.”
On the meta level, moral purity can apply whenever people hold firmly to a principle or policy. Republicans demand ideological purity in opposing all tax increases, and Kant gets accused of valuing his own moral purity more than another person’s life for refusing to lie to the murderer at the door. More generally, any misdeed feels “dirty”, so moral purity motivates people to avoid breaking any moral rule. This does seem to involve genuine feelings of purity/sanctity/contamination/disgust—witness the the large role of sin and purification in many religions, and the Lady MacBeth effect in the general populace (i.e., college sophomores). Violating a moral rule is a stain on you, which you may or may not be able to cleanse away.
Meta-level purity supplements a moral rule which has other bases. I don’t think that moral values against taxes and lies are based primarily on purity, even if there is some purity thinking involved in treating them as sacred values and refusing to compromise or consider tradeoffs. Lady MacBeth may have become obsessed with washing her hands but that does not mean that the (felt) wrongness of murder is due to it being a purity violation.
The principle that the government should not interfere in people’s sex lives sounds like another case where purity is operating at the meta level, where the primary foundation is something else. In this case, it’s probably foundation #6, liberty/oppression, which is activated particularly strongly for liberals because sexual restrictions have been a form of oppression against women and gay people.
There are other cases where people vehemently want the government to keep its hands off (e.g. guns on the right, abortion on the left), and the common thread seems to be that the individual should have the right to control something and do with it what they want, without outside interference. The purity foundation is recruited to help make these rules absolutist (e.g., people get very suspicious of any regulation that is even loosely related). It may also play some role in determining which particular rules are the ones that became absolutist, but if it is a factor I’d guess that it comes in third (at best), after how close/personal/important the issue is to people (e.g., involving control over your own body or personal protection) and how much of a threat to autonomy there is / has been.
The principle that the government should not interfere in people’s sex lives sounds like another case where purity is operating at the meta level, where the primary foundation is something else. In this case, it’s probably foundation #6, liberty/oppression
Then why don’t they apply the liberty principal to government regulation in other aspects of their lives?
The unsatisfying answer is that moral foundations theory doesn’t explain why the foundations get applied in the ways that they do—that differs between cultures and involves a lot of path-dependence through history. But Haidt’s theory does at least provide some guidance for conjecture, so I’ll speculate about why sexual liberty became important to liberals based on the liberty/oppression foundation.
The way that Haidt describes it, for American liberals the liberty foundation is primarily about wanting to protect sympathetic victims from oppression. Telling the story from that point of view, sexual restrictions have been a form of oppression, involving shunning and other social punishments for victims like women who had sex outside of marriage or men who loved other men. With the sexual revolution, liberals threw off these arbitrary and oppressive restrictions, and brought us much closer to a world where no one can stop you from being yourself (holding your sexual identity openly without fear of reprisal) or from having sex with who you want to, how you want to (as long as you are consenting adults).
Government regulation in many other aspects of people’s lives has not involved such obvious oppression of sympathetic victims.
Now, could someone return the favor and offer their speculation about how the purity foundation led liberals to value sexual liberty? Vladimir_M mentions that people tend to apply purity-based morality to sex, which is true, but they tend to apply purity at the object level as a reason to restrict sexual activities. Sexual liberty would be applying purity at the meta level as a reason to allow sexual activities. Sex can spread disease (the purity/contamination framework originally evolved for avoiding illness), involves the body in a way that is closely related to many elicitors of disgust, and because of its evolutionary importance people are prone to having strong intuitions & emotions about sexual activities that don’t readily fit in other foundations. So it’s understandable that people would tend to get squeamish about various sexual practices and want to restrict them based on purity concerns. It’s not clear to me how those purity concerns jump to the meta level and reverse direction.
Purity is an unusual foundation, since it can apply at the object level or the meta level. On the object level, people believe things like “don’t eat pork because it’s unclean” or “don’t have premarital sex because it takes away your purity.”
On the meta level, moral purity can apply whenever people hold firmly to a principle or policy. Republicans demand ideological purity in opposing all tax increases, and Kant gets accused of valuing his own moral purity more than another person’s life for refusing to lie to the murderer at the door. More generally, any misdeed feels “dirty”, so moral purity motivates people to avoid breaking any moral rule. This does seem to involve genuine feelings of purity/sanctity/contamination/disgust—witness the the large role of sin and purification in many religions, and the Lady MacBeth effect in the general populace (i.e., college sophomores). Violating a moral rule is a stain on you, which you may or may not be able to cleanse away.
Meta-level purity supplements a moral rule which has other bases. I don’t think that moral values against taxes and lies are based primarily on purity, even if there is some purity thinking involved in treating them as sacred values and refusing to compromise or consider tradeoffs. Lady MacBeth may have become obsessed with washing her hands but that does not mean that the (felt) wrongness of murder is due to it being a purity violation.
The principle that the government should not interfere in people’s sex lives sounds like another case where purity is operating at the meta level, where the primary foundation is something else. In this case, it’s probably foundation #6, liberty/oppression, which is activated particularly strongly for liberals because sexual restrictions have been a form of oppression against women and gay people.
There are other cases where people vehemently want the government to keep its hands off (e.g. guns on the right, abortion on the left), and the common thread seems to be that the individual should have the right to control something and do with it what they want, without outside interference. The purity foundation is recruited to help make these rules absolutist (e.g., people get very suspicious of any regulation that is even loosely related). It may also play some role in determining which particular rules are the ones that became absolutist, but if it is a factor I’d guess that it comes in third (at best), after how close/personal/important the issue is to people (e.g., involving control over your own body or personal protection) and how much of a threat to autonomy there is / has been.
Then why don’t they apply the liberty principal to government regulation in other aspects of their lives?
The unsatisfying answer is that moral foundations theory doesn’t explain why the foundations get applied in the ways that they do—that differs between cultures and involves a lot of path-dependence through history. But Haidt’s theory does at least provide some guidance for conjecture, so I’ll speculate about why sexual liberty became important to liberals based on the liberty/oppression foundation.
The way that Haidt describes it, for American liberals the liberty foundation is primarily about wanting to protect sympathetic victims from oppression. Telling the story from that point of view, sexual restrictions have been a form of oppression, involving shunning and other social punishments for victims like women who had sex outside of marriage or men who loved other men. With the sexual revolution, liberals threw off these arbitrary and oppressive restrictions, and brought us much closer to a world where no one can stop you from being yourself (holding your sexual identity openly without fear of reprisal) or from having sex with who you want to, how you want to (as long as you are consenting adults).
Government regulation in many other aspects of people’s lives has not involved such obvious oppression of sympathetic victims.
Now, could someone return the favor and offer their speculation about how the purity foundation led liberals to value sexual liberty? Vladimir_M mentions that people tend to apply purity-based morality to sex, which is true, but they tend to apply purity at the object level as a reason to restrict sexual activities. Sexual liberty would be applying purity at the meta level as a reason to allow sexual activities. Sex can spread disease (the purity/contamination framework originally evolved for avoiding illness), involves the body in a way that is closely related to many elicitors of disgust, and because of its evolutionary importance people are prone to having strong intuitions & emotions about sexual activities that don’t readily fit in other foundations. So it’s understandable that people would tend to get squeamish about various sexual practices and want to restrict them based on purity concerns. It’s not clear to me how those purity concerns jump to the meta level and reverse direction.