According to evolutionary psychologists, they way we think and act is all due to a scheme of gain and loss. People are attracted to pretty faces because it represents qualities like intelligence and happiness. Women are more attracted to attached males because the men seemed to possess good mating qualities. Yet, when we look at altruism, things get a little tricky. Altruism is an act done for the welfare of others. The purpose is not to benefit the individual. Doing something for the pleasure of someone else, even at the expense of yours, seems quite rare nowadays. Yet research shows that it's a common act for toddlers.
A study conducted on nearly a hundred two-year-olds found that toddlers genuinely enjoy helping out other people as much as they enjoy helping themselves. They will go out of their way to help you and even engage in paternalistic helping, which is when they ignore what you say to do something that will actually benefit you more! Some evolutionary psychologists might say that these acts are done so that they can gain status and recieve reciprocal favors in the future. However, a study published in Developmental Psychology says otherwise.
Measuring toddlers' body language and facial expressions, researchers found that even when a toddler recieves an unfavorable reward, they will overcome their disappointment when they realize the object is useful for someone else. In other words, the feeling of disappointment is replaced when they realize that another person could benefit from their posession--and they would gladly give it up. Although some toddlers smile more when discovering a favorable reward, those who did not did not lack significantly on the emotion scale. These results suggest that for young children, helping themselves and helping others are similarly rewarding.
Source material from Research Digest