# Simple Contagion
**Entity class:** Diffusion model
**Maturity:** Developed
## Definition
A **simple contagion** can spread after one sufficient exposure, making long weak ties effective transmission routes. Information awareness and some low-cost behaviors may approximate this model. High-cost identity or violent behavior usually requires the reinforcement represented by [[wiki/Complex Contagion|complex contagion]].
## Relationships
- **contrasted with:** [[wiki/Complex Contagion|Complex Contagion]].
- **used in:** [[wiki/Network Epidemiology|Network Epidemiology]].
- **terrorism application:** [[wiki/Terror Contagion Hypothesis|Terror Contagion Hypothesis]].
## Sources / Provenance
- [[research/A Network-Epidemiological Analysis of Radicalization and Real-Time Counterterrorism Observability|Network-Epidemiological Analysis]]