That animals help each other is far from a new observation, but it's puzzling nonetheless. If all that matters is survival of the fittest, shouldn't animals refrain from anything that fails to benefit themselves? Why help another get ahead? There are two main theories: First, that such behavior evolved to help kin and offspring, hence individuals who are genetically related. This promotes the helper's own genes as well. This "blood is thicker than water" theory explains, for example, the sacrifice of bees, who give their lives for their hive and queen when stinging an intruder. The second theory follows an "If you scratch my back, I'll scratch yours" logic: if animals help those who return the favor, both parties stand to gain. Mutual aid can explain political alliances, such as between Nikkie and Yeroen, who supported one another and shared the gains in power and sexual privileges.
Both theories concern the evolution of behavior, but neither tells us much about actual motives. Evolution depends on the success of a trait over millions of years; motives spring from the here and now. For example, sex serves reproduction, yet when animals couples, it's not out of a desire to reproduce. They don't know the connection: sexual urges are separate from the reason sex exists. Motivations lead a life of their own, which is why we describe them in terms of preferences, desires, and intentions, rather than survival value.
Image source: monkey pictures dot net