Obesity In a study published in the Journal of the American Me...

Question

Obesity In a study published in the Journal of the American Medical Association, researchers found that the length of time a mother breast-feeds is negatively associated with the likelihood a child is obese. In an interview, the head investigator stated, “It’s not clear whether breast milk has obesity-preventing properties or the women who are breast-feeding are less likely to have obese kids because they are less likely to be obese themselves.” Using the researcher’s statement, explain what might be wrong with concluding that breast-feeding prevents obesity. Identify some lurking variables in the study. 201

Accepted Answer

Welcome back everyone. In this problem, a study finds that children who play musical instruments tend to have higher math scores. The researcher claims that learning an instrument increases mathematical ability. What is a potential flaw in this conclusion? Identify some lurking variables that might affect both playing an instrument and math scores. A says the study shows an association, not causation, and that family income, parental education, and access to extracurricular activities are possible lurking variables. B says the study proves causation and only the type of instrument matters. C says the study is invalid and there are no lurking variables, and D says the study shows causation and only age is a lurking variable. Now, let's first think about what the study has found. What the researcher has found, OK? So they found that children who play musical instruments tend to have higher math scores, OK? Now this represents an association, not a causation. Now if we think about it here. It doesn't say anything about them directly being linked that playing musical instruments leads to higher math scores. This is the claim of the researcher, but if we think about it, is there anything else that might affect this conclusion? How about the family's income for that child, right? Uh, if they have a higher family income, then they may be able to afford to send their children to play musical instruments, but we don't know anything about the family incomes of the children in this study. How about their parental education? Their parents may might have a greater appreciation for playing musical instruments and again we don't know that about any of the children in the study. Likewise, we don't know what access to extracurricular activities these children may have. And if a school has uh a program for, you know, playing musical instruments, then they would be way more likely than. Another school that does not have the access to extracurricular activities to play musical instruments. So the point that we're making here is that all of these could influence both the likelihood of playing an instrument and their math scores confounding the results. If we want to make this conclusion that learning an instrument increases mathematical ability, then we would have to try and control all of these lurking variables. Therefore, A is the correct answer. The study shows an association, not causation, and family income, parental education, and access to extracurricular activities, among other things are possible lurking variables. We can be sure we're right if we review the remaining choices. Answer choice B says the study proves causation, but this is only an association, not causation. Instrument type is not the only factor. Choice C is also incorrect because it says that there are no lurking variables, but lurking variables can exist. So that invalidate and could invalidate, sorry, the conclusion. And in answer choice D, it says the study shows causation where only ages are lurking variable, but age is not the only possible lurking variable and causation has not been established either. That's why we're sure that answer choice A is the correct answer. Thanks a lot for watching everyone. I hope this video helped.

Key Concepts

Correlation vs. Causation

Lurking Variables

Confounding Variables and Bias

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