I could be wrong, but I think the security/background check takes a look at a lot of different things:
- military service
- political involvement (run for office, etc.)
- employment/education/association history
- countries visited
They also run name checks through various security (terrorist list/watch lists) databases.
This is why I think the majority of the time security/background screening is shorter for women than men in some countries. But then again, some people go through this process fast and others longer with the same kind of situation (nothing that would stand out).