2.1.2—Biological reductionism
- Syllabus
- First assessment 2027
- Objective
- 2.1.2
- Level
- SL
A biological explanation selects one level of the problem
Biological reductionism explains behaviour by reducing it to genes, brain structures or chemical processes. Holistic explanations include interactions across biological, cognitive, social and cultural levels.
Reductionism can produce testable mechanisms and targeted treatments, but a mechanism at one level may not explain onset, meaning or response differences. A drug effect supports a pathway hypothesis, not a complete account of a disorder.
An antidepressant that changes serotonin signalling may reduce symptoms for some patients. Therapy, stress exposure and social support can still influence whether the change is sustained.
Biological does not mean deterministic, and holistic does not mean untestable. State what the chosen level explains and what it leaves out.