Ideas On The Wane, Are Disappearing, Or Have Become Nearly G

Ideas on the wane, are disappearing, or have become nearly extinct in our lifetimes

This assignment is a brainstorming and short essay exercise. Please provide at least 2 examples of ideas/cultural features that fit each of the following 8 categories (2 for each category). You can draw the examples from your personal experience, the wider culture, or other cultures. You should be as specific as possible and elaborate sufficiently so I will know what you are talking about, and so that it's clear how your examples fit the categories you have put them in. Ideas that have spread during our lifetimes.

Ideas on the wane, are disappearing, or have become nearly extinct in our lifetimes. (It's relatively easy to think of technological gadgets that fall into this category. Try to come up with some social and cultural ideas too.)

Ideas that are "contagious" and rapidly spread from mind to mind.

Ideas that increase our survival and reproductive success (and are thus "adaptive" in biological terms)

Ideas that decrease our survival and reproductive success (and are thus "maladaptive" in biological terms)

Ideas that are transmitted from parents to children (AK "vertical transmission").

Ideas that primarily pass between peers (aka "horizontal transmission")

Ideas that pass from non-parental teachers, leaders, etc. to others (aka "oblique transmission")