Cultural traits spreading among peers within a generation move far faster than those passing from parents to children, and can change a population within years.
The transmission route determines the speed limit. Vertical transmission is bounded by the generation time and by a small number of models per learner; horizontal transmission has no such bound, since one individual can reach thousands within a season. Slang, technique, fashion and panic all travel this way, and so does anything carried by a medium that reaches peers directly.
In practice
- A working practice spreads across an industry in eighteen months because practitioners talk to each other and not because any firm decided.
- A playground game arrives in a school, saturates it in a fortnight and is gone by the next term.
- Standing
- Paired with vertical transmission, which is slower and more conservative.
- Further reading
- Wikipedia
- Subject
- Sociology & Culture
- Essay
- How societies hold together, sort people, and change