1. Environment
1.1. **Upland Ecosystem**
1.1.1. High elevation
1.1.2. Upland farming for food security
1.1.3. Great biodiversity
1.1.4. Children are taught to:
1.1.4.1. Navigate the area of the farm
1.1.4.2. Identify plants and animals
1.1.5. CHALLENGES
1.1.5.1. Kaingin / Slash-and-burn
1.1.5.2. Ancestral domains make them vulnerable to displacement
1.2. **Lowland Ecosystem**
1.2.1. Lower end of rivers meeting the plain
1.2.2. Less biodiversity
1.2.3. Upwelling encourages agriculture
1.2.4. SUSTENANCE
1.2.4.1. Domestication of animals
1.2.4.2. Cottage industries
1.2.5. Children are taught to:
1.2.5.1. Clean up coops
1.2.5.2. Feed animals
1.2.5.3. Breed animals
1.2.5.4. Haggle
1.2.6. CHALLENGES
1.2.6.1. Lack of farm-to-market shops
1.2.6.2. Opportunistic middlemen
1.2.6.3. Large-scale economics
1.2.6.4. Agricultural land being turned to industrial sites
1.3. **Coastal Ecosystem**
1.3.1. Near bodies of water
1.3.2. Children are taught to:
1.3.2.1. Fish
1.3.2.2. Whisper bid
1.3.3. CHALLENGES
1.3.3.1. Urban economics
1.3.3.2. Displacement
1.3.3.3. Climate Change
2. Origin
2.1. From the need of effective cooperation
2.2. Need to control sexual activity
2.2.1. MARRIAGE
2.2.1.1. Raising children
2.2.1.2. Commitment
2.2.1.3. Cultural
2.2.1.4. Continuing claim to right of sexual access
2.2.1.5. Control of sexual relations
3. Definition
3.1. Legal
3.2. Individual
3.2.1. Functional
3.2.2. Experiential
4. Evolution
4.1. Premodern
4.1.1. Marriage = union of clans
4.1.2. Authority on patriarch
4.1.3. Children exchanged as servants and apprentices
4.2. Modern
4.2.1. Most romanticized
4.2.2. Less children birthed
4.2.3. Separate family and productive spheres
4.2.4. Heavy engagement with motherhood
4.2.5. Isolation of nuclear family
4.2.6. Purpose of marriage is love and companionship
4.3. Postmodern
4.3.1. Rising divorce rates
4.3.2. Mass collegiate education
4.3.3. Women labor participation and suffrage
4.3.4. Rising standards of living