Question

Which of the following methods may not be used to understand growth patterns in humans?

• A. Repeat cross-sectional
• B. Cross-sectional
• C. Longitudinal
• D. Mixed Longitudinal

Hint:

Remember the three core methods for growth studies: Cross-sectional (snapshot of different ages), Longitudinal (movie of the same person), and Mixed (a series of short movies). "Repeat cross-sectional" is for comparing different snapshots taken years apart to see if people are growing differently now than they did in the past.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The question asks about the standard methodologies used in auxology (the study of human growth). The core goal is to understand growth patterns, such as the velocity of growth and the timing of growth spurts.
Step 2: Detailed Explanation:
There are three canonical methods for studying human growth patterns:
- Cross-sectional method: Different individuals are measured at various ages at a single point in time to construct a population-level growth curve.
- Longitudinal method: The same individuals are measured repeatedly over a period of time. This is the only method that can accurately study individual growth patterns and velocity.
- Mixed Longitudinal method: A combination of the above, where different age cohorts are followed for overlapping, shorter periods.
Now let's analyze the given option:
- Repeat cross-sectional method: This involves conducting a series of cross-sectional studies at different points in time (e.g., in 1980, 2000, and 2020). While this is a valid research design, its primary purpose is not to understand the fundamental pattern of human growth itself, but rather to study secular trends—that is, how the growth patterns of a population have changed over generations. The other three methods are directly designed to establish the pattern of growth for a given cohort or individual. Therefore, in the context of understanding the fundamental growth pattern, the repeat cross-sectional method is the outlier.
Step 3: Final Answer:
While all are valid research designs, the Cross-sectional, Longitudinal, and Mixed Longitudinal methods are the primary techniques used to establish and understand growth patterns. The Repeat Cross-sectional method is used to study changes in these patterns over time (secular trends) and is thus not a primary method for understanding the growth pattern itself.