Food

In part two chapter one of the book, Shackleton ordered the cook to add pieces of blubber into the stew for dinner so the crew would get used to eating it.  Though Shackleton may not have known this for sure, it was actually a great idea on his part.  The mere exposure effect essentially says that food that is eaten over and over again increases the person's liking for the specific food, in this case blubber.  In addition, the book says though some men removed the blubber from the stew, others ate it for the mere reason that they were starving.  This is an example of conditioned food preferences; when a person eats food when they are more hungry, they tend to prefer it to food they eat when they are less hungry.  Whether or not Shackleton realized it, he was paving the most positive way for his crew in terms of their less than desirable food situation.