Langford et al. (2006) investigated whether lab mice experiencing discomfort empathize with familiar mice also in discomfort.
Question:
Langford et al. (2006) investigated whether lab mice experiencing discomfort “empathize” with familiar mice also in discomfort. They conducted an experiment in which individual mice were given an injection of 0.9% acetic acid into the abdomen, causing mild discomfort. These mice were placed in one of three different treatments: (1) isolation, (2) with a familiar companion mouse (a cage mate) that was not injected, or (3) with a familiar companion also injected and exhibiting behaviors associated with discomfort. The response variable was the percentage of time that each treated mouse exhibited a characteristic “stretching” behavior (measured by abdominal constriction) indicative of discomfort. The data on 42 male mice are below.
a. Write a model statement for a linear model fit to these data. Indicate what each term in the model represents.
b. Write the corresponding statement for the null model.
c. Plot the data and add the predicted values for the null model and the “full” model. If mice empathize, focal mice should stretch most often, on average, when the companion mouse is injected. Is this the pattern in the data?
d. Is the fit of the full model significantly better than that of the null model? Carry out the appropriate hypothesis test.
Step by Step Answer:
Python Create a dataframe with the provided values for isolated companion not injected isolated 467 467 389 389 656 656 355 356 322 322 300 300 533 533 222 222 489 489 56 55 144 144 467 467 45 compani...View the full answer
The Analysis Of Biological Data
ISBN: 9781319226237
3rd Edition
Authors: Michael C. Whitlock, Dolph Schluter
