More than page content on a Page

When using the Pages in the latest WordPress I came across something odd: if i create multiple Pages with the same page slug (even though they have different parents) the content of the Pages with the same page slug all shows up when I view one of them.

For example, if I have these three different pages:

/distribution/what/
/aggregation/what/
/discussion/what/

I see the contents of all those three pages when I access /aggregation/what/ in my browser.

This must have something to do with The Loop I gatherm but I can not figure out in what way I can control The Loop so that it only lists the page contents of the page below “/aggregation/” when I look at “/aggregation/what/”.