Final answer:
The theme of the excerpt is that children often do not understand the consequences of their actions and can act cruelly towards others and one another as a result.
Step-by-step explanation:
The theme of the excerpt is Children often do not understand the consequences of their actions and can act cruelly towards others and one another as a result. The excerpt mentions that children can act however they wish around their peers because they are unaware of gender roles, which implies that they may not fully understand the impact of their actions on others. This theme is supported by the examples and information provided in the excerpt.