Your parent is probably skeptical because in 1906 total human powered winged flight time could reasonably be measured in minutes. Europe still believed it was a hoax. Pilots didn't even have instruments let alone a cockpit. If you were a pilot, odds are your name was either Orville or Wilbur.
Remember, the Wright brothers first flew in 1903.
As another reply points out, it was likely blimp, balloon or some other form of aviation that spurred the research on vestibular effects.
You forgot about Santos-Dumont, and many others besides.
Europe definitely didn't believe it was a hoax, in fact there were lots of people working at attempting powered flight.
That does not diminish the accomplishments of the Wright brothers in any way, but to make it seem as though Europe did not believe powered flight was possible is not true.
The time was simply ripe, lots of the bits and pieces had been developed by those that had gone before, such as Lilienthal (who built some pretty amazing gliders) and many others.
Remember, the Wright brothers first flew in 1903.
As another reply points out, it was likely blimp, balloon or some other form of aviation that spurred the research on vestibular effects.