Final answer:
The author supports the idea by explaining that humans are naturally selfish and tend to seek their own needs and desires in a survival situation. The author also discusses altruistic behaviors and how they can be explained through genetics and natural selection. Overall, the author presents evidence that people might not always behave as expected in a survival situation.
Step-by-step explanation:
The author supports the idea that people might not always act the way you would expect in a survival situation by explaining that humans are naturally selfish. The author states that people are selfish in both the narrow biological sense and in a broader social way. For example, when hungry, people seek food, and when tired, they seek rest. Additionally, people tend to want more of the things they desire, whether it be material goods or relational ones.
The author also discusses the concept of altruistic behaviors and how they are explained through genetics and natural selection. Although individuals may appear selfish, they may sacrifice themselves for the benefit of related individuals who share their genes. This can be seen in various examples, such as mammal parents sacrificing to care for their offspring or emperor penguins migrating to bring food for their young.
Overall, the author presents evidence that supports the idea that people might not always act as expected in a survival situation, as human behavior can be influenced by both selfish and cooperative tendencies.