Plz help. Here’s the question. How and when were you encouraged to be “seen and not heard”? How was this message conveyed?

Many situations can be related to this phrase. The message was conveyed in the way that you yourself as a vessel can be useful to others in maybe a situation of debate or other, but it wouldn't go beyond that. Therefore conveying that one may be useful as to be seen but seen as useless when heard.

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.

"harry t. moore (1905-1951) – civil rights activist, leader, and the first martyr of the civil rights movement. fannie lou hamer (1917–1977) – leader in the american civil rights movement; co-founder of the national women's political caucus and freedom democratic party. james farmer (1920–1999) – congress of racial equality."