# 49. Manipulation of bias and heuristics in decision making
## 49.5. Methodology/Refinements/Sub-species
### 49.5.36. Irrational escalation
This is the phenomenon where people justify increased investment in a decision based on the cumulative prior investment, despite new evidence suggesting that the investment decision was probably wrong. A manipulator uses this predilection to continue milking a victim, already committed to a cause, to pledge even further. Related to the "Gambler's fallacy".