If you can't show something's not cultural, have you shown anything aside from supporting/fighting prejudice with prejudice?
You can do a reasonably good job of showing (or at least suggesting) that something is biological rather than cultural if you show that (a) it exists in all or almost all human cultures and (b) it makes sense for human minds to be designed that way, ie. it's sensible from an evolutionary point of view.
If I understand correctly, Sex At Dawn is arguing that something (full-on no-holds-barred human polyamory) is natural despite the fact that (a) it is practiced in almost no cultures and (b) it doesn't make a lot of evolutionary sense.
Oh, and (c) it's not consistent with a helluva lot of other instincts we have, like the powerful sexual jealousy instinct. I suppose they'd claim that's just cultural.
You can do a reasonably good job of showing (or at least suggesting) that something is biological rather than cultural if you show that (a) it exists in all or almost all human cultures and (b) it makes sense for human minds to be designed that way, ie. it's sensible from an evolutionary point of view.
If I understand correctly, Sex At Dawn is arguing that something (full-on no-holds-barred human polyamory) is natural despite the fact that (a) it is practiced in almost no cultures and (b) it doesn't make a lot of evolutionary sense.
Oh, and (c) it's not consistent with a helluva lot of other instincts we have, like the powerful sexual jealousy instinct. I suppose they'd claim that's just cultural.