It was over a decade ago that Christian writer David Robertson mapped out the predicted trajectory of the ‘progressive’ slippery slope: “after SSM, it would be transgender and then the removal of gender altogether (this is all classic Queer Theory) and that this would then be followed by polyamory, polygamy, incest and then paedophilia”.
So, where are we, on the slope? Right here:
It’s legal to have a consensual sexual relationship with your siblings, parents, and grandparents in France. And Belgium. And Japan. And more than 70 other countries too. So how does NZ stack up? And why is it a moral dilemma? Explainer Editor Lloyd Burr compares our law.
By ‘explaining’, of course, they really mean, ‘making the case for’. As Robertson pointed out, when the MSM want to normalise something that very definitely isn’t normal, they will crank up “stories seeking to make a sympathetic ‘non-judgemental’ case”. Over to you, Stuff.
In New Zealand, there have been many documented cases on consensual incest, including Sarah* who was adopted and later entered a relationship with Steve, her biological father (Watch the 60 Minutes documentary here). They were charged after police raided their home. (*Not their real names).
Even this week, a man in his 30s was jailed for incest after having a consensual relationship with his grandfather. Being a same-sex relationship, there was no risk of offspring with genetic problems which left questions over why it even ended up in court.
So why is consensual incest so frowned upon today?
Does this sound very much like Robertson’s predicted “stories seeking to make a sympathetic ‘non-judgemental’ case” to you?
Stuff then veers to comparing New Zealand’s laws, which they characterise as if they’re confused and contradictory, and then the “dozens of countries” where it’s “legal” (although they don’t seem to have distinguished between ‘decriminalised’ and ‘legal’). For instance, JSA blog points out that “legality, in this case, only means there are no active penalties for consensual relationships between adult relatives”. As he further writes, incest may be decriminalised, but is deeply frowned upon in Japan.
As in so many things, legality does not equal acceptability. Serial cheating on one’s partner is legal, too, after all.
Ah, but Stuff is here to tell you how your moral revulsion is outdated and un-progressive, too!
“Disgust isn’t a very good guide to what is morally wrong or not,” says Massey University’s senior ethics, philosophy, and sexuality lecturer Dr Vanessa Schouten. “The fact that I find oysters pretty disgusting doesn’t mean it’s morally wrong for other people to eat them.”
Her main question is: Should the state be in the business of regulating consensual incestuous relationships?
Flashback to Robertson’s map: this is exactly the argument made for the push-off point of the slippery slope of same-sex marriage.
When it comes to the most obvious argument against incest, the high risk of birth defects, Stuff’s here to pooh-pooh that one for you, too.
“We don’t think it’s morally wrong for people with an inherited condition - maybe Hodgkin’s or something like that – to have sex. Nor for women over the age of 35 who have the same risk of their child having a defect”.
Just in case you’re missing the one-to-one matching of Robertson’s map, here it is so you just can’t miss it.
“People used to think homosexuality was wrong because it’s yuck. Clearly that’s a bad reason and clearly it’s not wrong. The fact some people used to think it was yuck wasn’t a good reason for thinking that it was wrong,” she says.

The only half-hearted argument we get against legalising incest is this:
“In real life, incest probably almost always does cause harm – particularly in cases involving close family members. Such relationships almost always involve exploitation and abuse,” [Schouten] says.
If you can’t see how this perfunctory rebuttal is set up to be knocked down, you’re probably a Stuff reader who swears black and blue there’s no slippery slope.
Meanwhile, I’ll leave you to ponder some more of Robertson’s warnings:
While paedophilia may still be the last cultural sexual shibboleth, I suspect that may not last long. After all, a society which believes that pre-teen children can determine and choose to change their gender has little argument against the claim that they should also be able to ‘choose’ when to be sexually active.
But that’s a topic for another Stuff ‘explainer’, no doubt.