EDIT: Beaten to the punch by CliffFletcher
I tried to find the context of the infographic. Apparently it was made by the National Museum of African-American History & Culture (a Smithsonian museum on the National Mall in Washington) and posted to this page:
https://nmaahc.si.edu/learn/talking-...pics/whiteness
It has since been removed (see
"African American Museum site removes ‘whiteness’ chart after criticism from Trump Jr. and conservative media" by The Washington Post), but this is what it looked like in its entirety:
From the
Post article:
The chart came from a 1978 book, “White Awareness: Handbook for Anti-Racism Training” by Judy H. Katz, according to the museum. It lists about 50 attributes white people used to describe their culture. These attributes, it said, “have been normalized over time and are now considered standard practices in the United States. And since white people still hold most of the institutional power in America, we all have internalized some aspects of white culture, including people of color.”
So the answer to your question, dear Locke, is 1978. This was a summary of what white Americans in 1978 thought defined "white culture".