AP Hug Unit 3.4 Study GuideAP Hug Unit 3.4 Study Guide

AP Human Geography | Unit 3.4 | Page 1

AP Human Geography

Unit 3.4: Types of Diffusion | Study Guide

Big Idea: Diffusion is the process by which a cultural trait, idea, innovation, or disease spreads from its place of origin (the hearth) to other places over time. Geographers classify diffusion by how it spreads: through the movement of people (relocation) or through the spread of the idea itself (expansion). Key Vocabulary

• Diffusion: The spread of a trait, idea, or innovation from one place to another over time and space. • Cultural hearth: The place where a trait or innovation originated and began to spread. • Innovation: A new idea, technology, or practice.

• Distance decay: The farther away something is from its source, the less likely it is to be adopted or the weaker its influence.

• Time-space compression: The shrinking of the time it takes for something to reach another place because of improved transportation and communication.

• Barrier: Anything that slows or blocks diffusion (mountains, oceans, language, religion, government restrictions, cultural resistance).

• Adoption: When a group accepts a new trait. Groups may accept, modify, or reject what reaches them. The Two Main Types

Relocation Diffusion

• A trait spreads when people physically move and carry it with them.

• The idea leaves the origin as people migrate and appears in a new, often distant, location. • Examples: Spanish speakers bringing Spanish to the Americas; immigrants opening ethnic restaurants and building religious sites in a new country; Hindu migrants carrying their religion to the Caribbean. Expansion Diffusion

• A trait spreads outward from the hearth while remaining strong in the origin area. The people do not need to move; the idea spreads.

• Three subtypes: contagious, hierarchical, and stimulus.

Subtypes of Expansion Diffusion

Type How It Spreads Example

Contagious

Spreads from person to person through direct

contact, like a wave. Distance and proximity

matter, and nearly everyone nearby is affected.

Flu spreading through a school; a viral

trend among friends; a rumor in a

community

Hierarchical

Spreads from people or places of power,

authority, or influence down to others. Jumps

across space, skipping areas in between.

Fashion from celebrities or major cities; a

trend from big cities to smaller towns; ideas

spreading from leaders

Stimulus

The core idea does not spread, but it inspires a

modified version or new product that fits local

culture.

Fast-food chains adding local menu items;

Japanese car makers adapting ideas to

local markets; a tech product that inspires

new versions

AP Human Geography | Unit 3.4 | Page 2

Quick Comparison

Relocation Contagious Hierarchical Stimulus

Driven by People moving Direct contact Authority or elite Inspiration,

adaptation

Pattern Appears in new far

places

Spreads outward

steadily Jumps across space Modified form

emerges

Keyword Migration Proximity Power, hierarchy Adapt, inspire

What Speeds Up or Slows Down Diffusion

• Speeds up: Better transportation, the internet and social media, trade, migration, globalization, shared language, and cultural openness.

• Slows down: Physical barriers (mountains, deserts, oceans), political borders and censorship, language differences, religious or cultural resistance, and distance decay.

• Time-space compression means diffusion today happens far faster than in the past, which is why trends now spread worldwide in days.

Common Mix-Ups

• Relocation vs. expansion: In relocation, the trait moves with people and may leave the origin. In expansion, the trait stays in the origin while it also spreads.

• Contagious vs. hierarchical: Contagious spreads by proximity to nearly everyone. Hierarchical spreads by status or power and can skip places.

• Hierarchical does not just mean 'big cities.' It can also be a person, class, or institution with influence. • Stimulus diffusion spreads the idea, not the exact thing. Look for adaptation or a modified product. • Diffusion is the process. Convergence is one possible result.

Practice Questions

1. Distinguish between relocation diffusion and expansion diffusion, and give one example of each. 2. A new dance trend spreads from a pop star to fans worldwide. Which type of diffusion does this best show, and why?

3. Explain how distance decay affects the diffusion of a cultural trait.

4. How has time-space compression changed the speed and pattern of diffusion?

5. Describe one barrier that can slow the diffusion of a cultural trait, and explain how it works. 6. A U.S. restaurant chain adds regional dishes in a new country. Identify the type of diffusion and explain your reasoning.

FRQ Tip: To identify the type, ask: Did people move? (relocation) Did it spread through contact? (contagious) Did it come from a person or place of influence, skipping areas? (hierarchical) Was it adapted into something new? (stimulus). Then use evidence from the prompt to support your answer.