An impulse can be defined as an instinctual urge. When people act impulsively, they act instinctively. Therefore, the question is essentially asking you to analyze the competing instinctual urges human beings have. For example, human beings may instinctually feel an urge to help others, or they may instinctually feel the urge to selfishly look out for only themselves. They may also instinctually feel the urge to hurt and even kill others.
In his novel Lord of the Flies, William Golding sets out to show humankind has a dual nature, an evil and a good nature, and both sides of the nature are displayed through our instinctive actions. Moreover, Golding shows that, without the constraints of civilized society, humankind will lapse into its more dominant nature--the evil side.
One clear example of the duality of human nature can be seen early on when Ralph meets Piggy. Though Ralph is generally a good guy, the sort people are naturally drawn to due to his good looks and ability to lead, he also displays a darker side when meeting Piggy. Piggy feels insulted at Ralph's display of selfishness when he shows a lack of interest at learning Piggy's name. Finally, Piggy feels compelled to say, "I don't care what they call me ... so long as they don't call me what they used to call me at school" (Ch. 1). Ralph further displays selfishness and an inability to empathize by breaking down into shrieking fits of laughter at the name of "Piggy." To make matters worse, he introduces Piggy as "Piggy" to the rest of the boys. All of these instinctive actions of Ralph cause Piggy very severe and undeserved hurt. We also know they are instinctive because Ralph took action before stopping to think.
However, contrary to Ralph's displays of selfishness, he is the only boy on the island who has the sense to think of building shelters and a signal fire, which shows he values life and feels an instinctive desire to protect life, including the lives of others around him.
The duality of human nature can be seen in other actions of the boys all throughout the book. Plus, Golding emphasizes his point that evil is the dominant nature by ending the book with such evil, instinctive actions as murder.