Explanation
Correct answer: B.
Choice B is the best answer because it most logically completes the text’s discussion of Hillemacher’s study of visual self-recognition in chickens. According to the text, when a predator is nearby, chickens cry out in warning if another chicken is present but remain silent if alone to avoid attracting the predator’s attention. The text explains that Hillemacher set up one condition in which a subject was alone and could see its reflection in a mirror and another condition in which the subject could see another chicken, and then presented an image of a hawk (a predator). It follows that if chickens aren’t capable of recognizing themselves visually in a mirror, the subject likely would cry out a warning in both conditions; in the first condition because it would perceive its reflection as another chicken—that is, it would think another chicken is present—and in the second condition because it would see that another chicken is actually present.
Why the other choices are wrong
Choice A
Choice A is incorrect because the text suggests that regardless of chickens’ ability to visually recognize themselves in mirrors, the subject in the second condition would cry out a warning because another chicken is actually present. Further, if chickens do lack visual self-recognition, the subject in the first condition likely would also cry out because it would think its reflection is another chicken.
Choice C
Choice C is incorrect. The text does suggest that if chickens lack the ability to visually recognize themselves in mirrors, the subject would cry out a warning in the first condition because it would think its reflection is another chicken. However, the text also indicates that regardless of their capacity of self-recognition, chickens cry out a warning when other chickens are present, and another chicken is present in the second condition. Therefore, both conditions—not just the first one—likely would elicit an audible response from the subject.
Choice D
Choice D is incorrect because the text indicates that the study was focused on determining whether chickens recognize themselves visually in a mirror or instead perceive their reflections as other chickens; there’s no suggestion that a lack of self-recognition would cause a chicken to confuse its reflection with the image of a hawk.
Student discussion
marcosat 5 likes
Really fun question! Already knew the outcome halfway through the text. The key idea is to generalize things. The first half of the text tells us that if: 1) chicken alone, chicken silent when danger 2)chicken together, chicken warn when danger. Therefore, it is logical to test whether a chicken will still scream out when it is shown a reflection of itself and a hawk. Thus saying: Chicken 'think' with others, chicken scream when hawk (really just reflection), thus it does not recognize itself. So they would just scream if they cannot recognize themselves.