“Studies show…”
Two words that end arguments. And they shouldn’t—because in the world of sex research, they’re doing a lot less work than people think.
I build my coaching practice on evidence. Good research has genuinely changed lives for the couples I work with. But I’ve also watched confident-sounding statistics get weaponized to sell things, dismiss real harms, and talk people out of their own convictions. So here’s the toolkit I use—and the one I’m teaching my six kids.
The short version: Sex research is genuinely valuable, but it has structural limits most people never hear about. It’s almost entirely correlational (you can’t ethically assign people to watch porn), it’s almost entirely self-reported (nobody follows couples into the bedroom), it’s constrained by privacy and legal obligations, and—like any field—it carries the assumptions of the people conducting it. Knowing these limits doesn’t make you anti-science. It makes you a better reader of science.
First: good sex research is a genuine blessing
Let me start here, because I don’t want to be misread as a skeptic of the whole enterprise.
A frequent concern in my practice is a wife who struggles to experience pleasurable sex. Giving that couple accurate, research-backed information about anatomy and physiology—paired with practice—often produces real change. Better sexual experiences follow, and marital satisfaction tends to rise with them. That’s good science doing good work.
Another example I lean on constantly: Rosemary Basson’s model of responsive versus spontaneous desire (Basson, 2000). That single framework has rescued countless marriages from the false belief that a lower-desire spouse is broken. Research did that.
So the goal isn’t cynicism. It’s discernment.
Limit #1: Correlation is not causation—and here it can’t be
This is the big one, and it’s baked into the field permanently.
In most sciences, you establish causation with a controlled experiment—randomly assign people to a condition and see what happens. You cannot do that here. It would be flagrantly unethical to randomly assign one group of people to start using pornography, or to have sex outside of marriage, just to measure the damage. No ethics board on earth would approve it, and rightly so.
The consequence: nearly all sex research is correlational. It can tell you two things travel together. It cannot, by design, prove which one caused the other. Does pornography use erode marital happiness—or do unhappy marriages drive people toward pornography? The honest answer is that a correlational study can’t settle it.
Now watch how that gets exploited. The pornography industry leans on this limitation deliberately, insisting that the documented harms are “only correlation, not causation.” Technically true. Practically dishonest—because they know full well that the causal study they’re demanding can never ethically be run. That’s not a scientific argument. It’s a rhetorical shield built out of an ethical constraint. (I lay out what the correlational evidence does show in the real cost of pornography.)
Limit #2: Almost everything is self-reported
Researchers do not follow test subjects into their bedrooms. So virtually all the data on private sexual behavior comes from people telling researchers what they did—filtered through memory, embarrassment, ego, and wishful thinking.
Here’s a test I love. Ask a husband and wife separately how often they had sex last week. You will frequently get two different numbers—about the same marriage, over the same seven days. Not because anyone is lying, but because subjective experience and memory genuinely diverge.
Or consider studies reporting average penis size, where men are handed instructions and asked to measure themselves in private. Some measure incorrectly. Some, shall we say, round generously. And that’s the data.
So when you see a precise-sounding statistic about what people do behind closed doors—hold it loosely.
Limit #3: Privacy and legal constraints shape what can be studied
Sex research often touches behavior that is stigmatized or outright illegal. Protecting participants matters enormously—but researchers sometimes carry legal obligations to report harm, which changes how honest participants are willing to be.
Think about studying teenage sexual activity. A teenager may withhold the most important details out of fear that a perpetrator could find out and retaliate. And some research simply cannot ethically be conducted at all, because it would risk re-traumatizing survivors of abuse or trafficking.
Which means: the gaps in the literature aren’t random. Some of the most important questions are the hardest ones to study, so they’re studied least. Absence of evidence, here especially, is not evidence of absence.
Limit #4: Researchers have worldviews too
This one needs care, because it’s easy to abuse. Bias doesn’t mean the findings are fake, and “they’re biased” is not a valid reason to dismiss research you dislike.
But it’s fair to say that sexology as a field skews politically progressive, and that homogeneity can create genuine blind spots (Levy, 2015). Not fabrication—blind spots. Religious commitment, covenant, chastity, and lifelong marriage may go unmeasured, or get treated as confounding variables to control away rather than as goods worth studying. If nobody in the room thinks a variable matters, nobody puts it in the model.
The right response isn’t to reject the science. It’s to read widely, notice which questions aren’t being asked, and stay alert to assumptions—including your own.
The five questions I teach my kids
Critical thinking is a skill, and it’s teachable. When my teenagers encounter a claim about sex—in a headline, a health class, or a TikTok—here’s the grid:
- Is this correlation or causation? Almost always the former. Do they claim more than they’ve shown?
- Where did the data come from? Self-reported survey? Small sample? Who was left out?
- Who benefits from this conclusion? Follow the incentive. An industry with a financial stake in your behavior is not a neutral narrator.
- What’s the strongest case on the other side? If you can’t state it fairly, you don’t understand the issue yet.
- Is this a fact, or an interpretation of a fact? The finding and the pundit’s spin on it are two different objects.
That’s not cynicism. That’s literacy. And it’s one of the most protective gifts you can hand a teenager in an era where anyone with a ring light can say “studies show.”
And then there’s the deeper way of knowing
For a Christian, there’s a source of knowledge that no study design can replicate. Jesus taught that the Spirit of truth guides us into all truth (John 16), and Paul wrote that the Spirit searches out even the deep things of God (1 Corinthians 2).
This isn’t a way of dodging evidence—I’ve just spent an entire article arguing for reading evidence carefully. It’s a recognition that a life lived in line with God’s commandments invites a kind of discernment that peer review can’t supply. Teach your kids to think rigorously and to listen for that.
Where to go for trustworthy information
A few sources I recommend without hesitation. Dr. Douglas Rosenau’s A Celebration of Sex remains a solid, faith-rooted guide to sexual intimacy (Rosenau, 2002). Brad Wilcox’s Get Married makes a well-researched case to young adults for the social, economic, and personal benefits of marriage (Wilcox, 2024). And our own Intimately Us app and the Get Your Marriage On podcast exist precisely to give couples evidence-based, biblically grounded guidance.
Being a careful reader of research is one reason couples trust me with their marriages. If you want that kind of grounded, honest guidance in your own relationship, you can join our Next Level program or work privately with a coach.
Frequently Asked Questions
Ask five questions: Is this correlation or causation? Was the data self-reported? Who funded it, and who benefits from the finding? Is the sample big and representative? And has it been replicated? Most sex research is correlational by necessity, which means it can show that two things travel together — not that one causes the other.
Because the ethical experiment doesn’t exist. You can’t randomly assign people to use pornography, or to have sex before marriage, and then measure the damage. So researchers rely on correlational studies — and industries that profit from a behavior often exploit that limitation, insisting nothing has been ‘proven.’ That’s a rhetorical move, not a scientific one.
Only partly. Researchers don’t follow people into the bedroom, so nearly everything is self-reported — and memory, embarrassment, and wishful thinking all distort the numbers. Spouses asked the same question about their own marriage routinely give different answers. Treat precise-sounding statistics about private behavior with healthy caution.
It can. Sex research skews politically progressive, which doesn’t make it wrong — but it can create blind spots, especially around religious values, marriage, and commitment, which may go unmeasured or get treated as confounds rather than goods. Read widely, notice what questions aren’t being asked, and hold conclusions loosely.
References
Basson, R. (2000). The female sexual response: A different model. Journal of Sex & Marital Therapy, 26(1), 51–65. https://doi.org/10.1080/009262300278641
Levy, D. J. (2015). Political values and sex research. Psychology Today.
Rosenau, D. E. (2002). A celebration of sex: A guide to enjoying God’s gift of sexual intimacy (2nd ed.). Thomas Nelson.
Wilcox, W. B. (2024). Get married: Why Americans must defy the elites, forge strong families, and save civilization. Broadside Books.
