Stephanie was always chatting away at home with her siblings and parents. she was considered shy when out in public, never speaking to others. however, her parents weren't concerned until she started preschool. she has been in school for four months and still hasn't spoken to her teacher or classmates. stephanie is displaying signs of:

"social anxiety"

Explanation: It's basically a fear of talking to people and certain situations. While she is more comfortable while around people she knows she is terrified of other unknown people.

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.