Question

In Exercise \(1.18,\) we ask whether experiences of parents can affect future children, and describe a study that suggests the answer is yes. A second study, described in the same reference, shows similar effects. Young female mice were assigned to either live for two weeks in an enriched environment or not. Matching what has been seen in other similar experiments, the adult mice who had been exposed to an enriched environment were smarter (in the sense that they learned how to navigate mazes faster) than the mice that did not have that experience. The other interesting result, however, was that the offspring of the mice exposed to the enriched environment were also smarter than the offspring of the other mice, even though none of the offspring were exposed to an enriched environment themselves. What are the two main variables in this study? Is each categorical or quantitative? Identify explanatory and response variables.

Short answer

The two main variables are 'living conditions' and 'intelligence', the former being categorical and the latter being quantitative. The explanatory variable is 'living conditions' and the response variable is 'intelligence'.

Step-by-step solution

Identify Main Variables

The first step in answering this question is to determine the two main variables in the study. In this case, they are the 'living conditions' and 'intelligence (speed in navigating mazes)' of the mice.

Classify Variables as Categorical or Quantitative

The next step is to determine whether each variable is categorical or quantitative. The 'living conditions' variable is categorical because it can be divided into two distinct categories: mice that lived in an enriched environment and mice that did not. The 'intelligence' variable is quantitative because it can be measured by how quickly the mice navigate mazes.

Identify Explanatory and Response Variables

The final step is to identify which of the variables is explanatory and which is the response. Here, the 'living conditions' variable is explanatory because it explains or can have an effect on the response variable. Therefore, the 'intelligence' variable is the response because it responds to or can be affected by the explanatory variable.