Student or Learner
Which does this "them" refer to? "What others are doing" or "others"? I think "them" is plural, so it must refer to "others" and "what others are doing" can't function as a plural form. And I think "ignore the drivers" supports the idea.
28)In most situations, social proof is very useful. The restaurant with the fullest parking lot usually does have the best food. You will make (A) fewer / more mistakes in life by paying attention to what others are doing than by neglecting them. For example, when you are driving down the expressway and all the cars in front of you start changing lanes, those drivers probably know something you donít know and you should change lanes, too. If you (B) follow / ignore the drivers, you may hit something in the road and be in a serious car accident. But sometimes people create social proof for a bad purpose. You should be careful about this kind of social proof, because it is used to (C) benefit / mislead you.
Yes, I think you are correct. The "them" refers to "others".