That's interesting. The 'White parent with kids' search, I actually expected to see different colour children, but I'm not sure why. Maybe because of the way it's prefixed, but if you change out the word 'White' with 'Black' or 'Asian' the opposite does not occur.
The American Inventors search has the top sites claiming exactly what you are pointing out. Is that like a self fulfilling prophecy? Is that site populating the top images? In fact, if you search those words you get educated on what you fear as soon as you click on the top sites. Therefore, is google really hiding something? of are they being made to look so?
Also, the second suggestion google pops up after ;'american inventors' is 'american inventors google search reddit'.......again going on about what you are stating. Seems to me google is just showing the most popular searches?