In regards to the Netherlands, correlation does not equal causation.
Very good point. You cannot scientifically or statistically prove causation due simply to a proof of correlation. In fact, that would be a
cum hoc ergo propter hoc fallacy.
However,
Blankenhorn points out how that argument misses the point and is effectively a kind of red herring...
Neither Kurtz nor anyone else can scientifically prove that allowing gay marriage causes the institution of marriage to get weaker. Correlation does not imply causation. The relation between two correlated phenomena may be causal, or it may be random, or it may reflect some deeper cause producing both. Even if you could show that every last person in North Carolina eats barbecue, you would not have established that eating barbecue is a result of taking up residence in North Carolina.
When it comes to the health of marriage as an institution and the legal status of same-sex unions, there is much to be gained from giving up the search for causation and studying some recurring patterns in the data, as I did for my book The Future of Marriage.
...The correlations are strong. Support for marriage is by far the weakest in countries with same-sex marriage. The countries with marriage-like civil unions show significantly more support for marriage. The two countries with only regional recognition of gay marriage (Australia and the United States) do better still on these support-for-marriage measurements, and those without either gay marriage or marriage-like civil unions do best of all.
...Certain trends in values and attitudes tend to cluster with each other and with certain trends in behavior. A rise in unwed childbearing goes hand in hand with a weakening of the belief that people who want to have children should get married. High divorce rates are encountered where the belief in marital permanence is low. More one-parent homes are found where the belief that children need both a father and a mother is weaker. A rise in nonmarital cohabitation is linked at least partly to the belief that marriage as an institution is outmoded. The legal endorsement of gay marriage occurs where the belief prevails that marriage itself should be redefined as a private personal relationship. And all of these marriage-weakening attitudes and behaviors are linked. Around the world, the surveys show, these things go together.
...We cannot demonstrate statistically what exactly causes what, or what is likely to have what consequences in the future. But we do see in country after country that these phenomena form a pattern that recurs. They are mutually reinforcing. Socially, an advance for any of them is likely to be an advance for all of them. An individual who tends to accept any one or two of them probably accepts the others as well. And as a political and strategic matter, anyone who is fighting for any one of them should--almost certainly already does--support all of them, since a victory for any of them clearly coincides with the advance of the others. Which is why, for example, people who have devoted much of their professional lives to attacking marriage as an institution almost always favor gay marriage. These things do go together.
In addition, Kurtz himself
acknowledges that you can't scientifically prove causation through correlation, but also makes some interesting observations...
...It’s certainly true that numbers alone can’t prove causation. If a survey shows that cities where people drink a lot of orange juice also tend to have large traffic jams, that doesn’t prove orange juice causes traffic jams. The correlation could be a total coincidence, or the commonality might have to do with some third factor, like the weather. But the impossibility of proving causation from numbers alone doesn’t mean that it’s impossible to put together a persuasive causal case.
...you’ve got to follow up the numbers with a deeper case substantiating the causal claim. You’ve got to examine possible alternative causes, and give good reasons why those alternative causes ought to be either rejected, or supplemented, by others. And you need to explain why the link...is likely to be more than coincidence.
...I’ve offered a case on the causal effects of same-sex marriage, and in doing so I’ve gone way beyond mere numbers. I’ve acknowledged and examined possible alternative causes, and argued that, important as they often are, these alternative causes do not by themselves suffice to make sense of the current decline of European marriage. I’ve also offered a close look at the attitudes toward institutional marriage favored by European proponents of same-sex unions. Put that all together, and I think it allows you to say that we are dealing with more here than orange juice and traffic jams.
Again, it is true that you cannot scientifically or statistically
prove causation due simply to a proof of correlation. However, this debate is a social and political one, not a scientific one. It is
informed by scientific evidence, but goes well beyond the empirical conclusions allowed by science.
Without being able to conduct scientific experiments it is impossible to
prove causation. "Social experiments" cannot eliminate variables to the degree necessary to prove causation, and are very likely to have far reaching, irreversible and severe effects that are as likely to be negative as positive. So determining causation between two correlated effects is drawn from argument and probability based on what the evidence suggests.
According to
this link, "To say that correlation does not
suggest causation' is false: A demonstrably consistent correlation often suggests some causal relationship (or implies it, in the casual sense of the word). What correlation does not do is
prove causation."
Still, it is very easy to fall into a
post hoc ergo propter hoc fallacy, so you have to be very careful to avoid it.
As
this link on post hoc ergo propter hoc points out, "The fallacy lies in coming to a conclusion based
solely on the order of events, rather than taking into account other factors that might rule out the connection."
So what is necessary is to, "examine possible alternative causes, and give good reasons why those alternative causes ought to be either rejected, or supplemented, by others. And you need to explain why the link...is likely to be more than coincidence."
Kurtz claims to have done that when he says, "I’ve acknowledged and examined possible alternative causes, and argued that, important as they often are, these alternative causes do not by themselves suffice to make sense of the current decline of European marriage. I’ve also offered a close look at the attitudes toward institutional marriage favored by European proponents of same-sex unions."
Basically, what needs to be done in regards to causation in a social and political debate is to show that the proposed explanation is the most reasonable, considering all the evidence in context.
In light of the placement of the burden of proof dictated by the precautionary principle in favor of tradition, a
probable causation is more then enough to be considered a reasonable objection to a proposed change.
Whew!
That was a
very good point to raise, TommyB. I actually hadn't considered that! Took a while for me to develop a response.
Once again, sorry 'bout the long post.
