The results of statistical testing are also shown on the graph in Question 1. Notice that, in these tests, John Hoogland chose to compare the alarm call frequency of prairie dog's of the same assigned sex to one another (male or female) rather than compare males to females. For instance, the p-value of 0.019 refers to the difference in alarm call frequency among assigned males with or without kin living in their home coterie. Similarly, the p-value of 0.027 refers to the difference among assigned females with or without kin living in their home coterie. By limiting statistical comparisons of prairie dog calling behavior to animals of the same assigned sex, Hoogland is treating assigned sex as a ____. dependent/response variable control group standardized variable experiment group independent/explanatory variable