The concept described as being triggered by external circumstances is known as:

• A. Normative aging
• B. Contextual aging
• C. Reactive effects
• D. Cohort effect

Answer: (C)

The idea being tested is how development or behavior can change in response to things happening outside the person. This is captured by reactive effects: when external circumstances—like health changes, new responsibilities, or family events—trigger a person to adapt in a new way. It’s about the dynamic response to the environment driving change.

Normative aging refers to typical, age-related changes that happen over time regardless of specific external events, so it isn’t about a trigger. Contextual aging highlights how the surrounding environment shapes aging more broadly, but it doesn’t emphasize the hit-by-hit triggering of change. Cohort effects are differences that come from being born in a particular time period, not from an immediate environmental trigger acting on an individual. An example of reactive effects would be someone changing their daily routine in response to a major health setback or a new caregiving role imposed by a family event.