Why We Removed Three Statistics From Our Homepage

For years the front page of this site opened with three numbers. Fifty per cent of men and women cheat at least once in their marriage. People who suspect their partner is cheating are right 85% of the time. Seventy per cent of married women and 54% of married men never find out about their spouse’s infidelity.

They are gone. We went looking for the studies behind them and could not find any. Not a weak study, not a dated one. Nothing at all.

Where those numbers actually came from

They came from other websites. That is the whole provenance. Infidelity statistics circulate around the private investigation industry the way a good story circulates around a pub, and each site that repeats a figure lends it a little more weight to the next site that copies it. Eventually a number that nobody measured is on a hundred pages and looks like common knowledge.

The 85% figure is the clearest example. Think about what it would take to measure it. You would need a large sample of people who suspected their partner of cheating, a reliable way of establishing whether each partner was in fact cheating, and no selection bias in who agreed to take part. No such study exists in Australia or anywhere else. The number is a guess that hardened into a fact through repetition.

The other two are the same. A range of 50% for lifetime infidelity is roughly double the highest credible measured figure. And 70% of married women being unaware of a partner’s infidelity is, by definition, not something a survey can establish, because the people in that category are the ones who would answer no.

What we put in their place

Two statements, both linked to the research behind them.

The first is the closest thing to a solid measured infidelity figure that exists in the English-speaking world. A US Institute for Family Studies analysis of General Social Survey data found that 20% of married men and 13% of married women reported having sex with someone other than their spouse while married. The General Social Survey is a long-running, properly sampled American survey, and the figure is self-reported, which almost certainly makes it an undercount. We say it is US data, because it is.

The second is Australian. In a Relationships Australia survey of around 1,800 visitors to its website, most respondents said emotional disconnection is the main cause of infidelity. Note what that survey measures and what it does not. It asks people about causes and perceptions. It does not measure how many Australians have actually cheated, which is why we do not quote a percentage from it.

The Australian number does not exist

This is the part most sites get wrong. There is no Australian equivalent of the Institute for Family Studies figure. No properly sampled national study has measured how many Australians have been unfaithful. So when you see “40 to 70% of Australian marriages experience an affair”, or “66% of Australian couples”, or any other figure attributed to Australian marriages, one of two things has happened. Either an overseas statistic has been relabelled as Australian, or a perception survey has been misread as a behavioural one.

We would rather say we do not know than quote a number we cannot stand behind.

Our own results are our own data

One number on our sites is ours to quote, and that is our success rate. Across the group we describe it as around 95%, and we always say what it rests on: our own client outcomes over 20 years. It is not a published study and we do not present it as one.

It is also worth being precise about what it counts. A successful matter is one where the client got a clear answer, and sometimes the clear answer is that a partner has been faithful the whole time. That is a good outcome, and it is included. We do not claim that 95% of our clients discover an affair, because that would be a different claim and not one the evidence supports.

Why bother

Partly because search engines and AI systems increasingly cross-check claims against their sources, and a page full of unsourced percentages is a liability rather than an asset. But mostly because of who reads these pages. People land here at one of the worst points in their life, trying to work out whether their instincts are right. Feeding them an invented statistic to make them feel less alone is not a kindness. Telling them what is actually known, and being honest about what is not, is.

If you are at that point now, the useful thing is not a percentage. It is a clear answer about your own situation. That is what we do.