48. In order to establish a cause-and-effect relationship between regular exercise and improved cognitive functioning in older adults, a researcher would need to do which of the following?
Answer: C
Randomly assigning a group of adults over the age of 55 to either an exercise or an alternative sedentary activity is essential for establishing a cause-and-effect relationship.
This approach allows for a controlled environment where the effects of exercise on cognitive functioning can be measured accurately over time. By comparing results before and after the intervention, the researcher can draw clearer conclusions about the impact of regular exercise.
A) Survey persons over the age of 55 to determine their activity level and exercise routines, then administer assessments of verbal and spatial cognitive abilities.
While this option collects valuable data about current exercise habits and cognitive performance, it does not establish a cause-and-effect relationship. Correlational studies cannot definitively show that exercise leads to improved cognitive functioning, as other variables may influence both factors.
B) Administer cognitive assessments to people living in a retirement community that provides opportunities for active lifestyle and to people living in a retirement community that does not provide such opportunities.
This option compares cognitive functioning between two groups with different lifestyle opportunities, but it still falls short of establishing causation. The presence of confounding variables in the community settings could affect the results, making it unclear whether exercise itself is responsible for any observed differences.
C) Randomly assign a group of adults over the age of 55 to either an exercise or an alternative sedentary activity, and administer a cognitive assessment at the beginning of the study and again after three months.
This is the correct approach as it includes random assignment, which helps eliminate bias and confounding variables. By assessing cognitive performance before and after the intervention, the researcher can effectively determine the direct impact of exercise on cognitive functioning.
D) Conduct a case study of a 60-year-old individual who lifts weights competitively.
A case study provides in-depth information about a single individual but lacks generalizability. It cannot establish a cause-and-effect relationship applicable to the broader population of older adults, as it does not involve a systematic approach or comparative analysis.
E) Administer cognitive assessments to members of a biking club and to a book discussion group for senior citizens.
This option compares two distinct groups but does not control for other variables influencing cognitive outcomes. Like some previous options, it fails to establish causation, as differences in cognitive abilities could arise from various factors beyond exercise.
Conclusion
The correct answer, option C, is the only choice that utilizes a controlled experimental design necessary for establishing a cause-and-effect relationship. All other options either rely on observational data or lack the necessary controls to ascertain the direct impact of regular exercise on cognitive functioning in older adults. Thus, only option C provides a valid framework for testing the hypothesis effectively.