Native American fishing trap from the Pacific Northwest. The analogy here is that our biases make it easier to accept ideas from certain directions (Source: Stewart 1977, p. 114).
native-american-fishing-trap-stewart-1977
Patrick F. Clarkin, Ph.D.
biological anthropology, war & health, growth & development, being human
Patrick F. Clarkin, Ph.D. 
Could I have the full reference for Stewart 1977 please? I work in the northwest for the Coeur d’Alene Tribe and don’t think we have this in our library
Sure. This is where I found it. https://www.google.com/books/edition/Indian_Fishing/fudyXm4KMpQC?hl=en