“The effect can occur through accumulated choices.”

This means no single person necessarily decides:

“Let's make colonialism dominant.”

Instead:

Editor 1 chooses an article on colonialism.

Funding committee funds another colonialism project.

Conference accepts another paper.

Publisher publishes another book.

University adds another course.

Researchers cite these works.

Students become interested.

More research follows.

Each decision may be individually reasonable.

But the accumulated effect of many decisions can produce a large systematic pattern.