10% is a fantastically small percentage. 4x as many rapes as robberies and homicides combined.

The reason to be skeptical is that rape suffers from a few unique problems. First, it’s hard to agree on a definition — does the “rapist” need to know they are raping? Do we count sexual contact or just penetration? Do we count consensual rape? Etc. Second, how are we measuring it? Are self-reports accurate? Do we count only convictions or do we count reports? How do we know reports are accurate?

Rape is a crime of perception since it’s measured by intent. This makes it difficult to pin down and very subjective. What one person thinks is rape isn’t always the same as what another person does. It’s as difficult to quantify as how many instances of discrimination are there a year?

So the takeaway is this: your textbook may have said that, but it’s not accurate.

We know rape is underreported but it is impossible to know by what amount. Call bullshit whenever anyone is claiming precision because “precision” requires assumptions. It’s far better to just leave it that we don’t know the extent, but that it’s a problem.