Brenda was completing a 1-year internship in Baltimore. Luckily, she found an apartment not far from school. To get     some exercise, acquaint herself with her new surroundings, and listen to her music, she walked to and from school     every day. The 2-mile route took her past Johns Hopkins University, an extremely busy campus teeming with     students and passersby. On her way home one day, music blasting in her ears, Brenda suddenly found herself head     down in a muddy ravine right in front of the universitys main quad. Someone had come up from behind and pushed     herhard. She was not hurt, but at that moment, she was head down, feet sticking up in the air, in full view of     everyone on the Hopkins campus. Attempting to right herself, she wondered why none of the many onlookers     offered their assistance.

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an explanation about why none of the onlookers offered their assistance. Your explanation must be informed by social psychology theory and research.