Whenever I’m with some of my younger siblings they act as if nothing has happened; it makes it seem like they don’t care even though I know they do. Why are they acting this way?
Children at varying ages experience death differently. Very young children do not understand the concept of irreversibility, so they do not understand that once someone is dead, that someone won't come back.
School-age children may have a better concept of death, but are nonetheless children “first.” Playing may be a way of working out what happened. They may either play with superheroes who rescue someone or have magical powers to cure someone. Other times, children play simply because that is what they do. However, when your younger siblings act as though nothing has happened, this does not mean they don’t recognize that someone has died or are indifferent, but rather, it could be an indication that they are experiencing death differently than older children or adults.
There is no one reaction that all children undergo, however. For instance, sometimes children do show other signs of their experience of death, like by acting out or being very sad. This can sometimes happen months or longer after the death, or immediately.