Why is it important for criminologists to study the behavior of preadolescents?

You might have heard this before, but the base is the most important part of a structure or building, in this case it may be called the "psychological structure".

Childhood tends to mark and form us the most because it's an age where we encounter new things on a constant basis and, as you might have noticed even when you grew up, the first encounter with a certain object or person will usually involuntarily influence the experience, feelings and thoughts that follow after, regarding that respective thing.

Also, lack of experience (which you have plenty of when young) leads to you understanding and perceiving a thing in the wrong way, especially when someone is not there to explain it to you or guide you through. The image you have of the world is just your own and sometimes you can't compare it to something else because you don't know how to or that you're supposed to.

This is usually the case with families with a history of violence, drug or alcohol abuse, families that end up divorcing and families in which a child has been molested (there are more specifics, but this is a basic general/overall view).

They see only violence, fear, people getting hurt, so they tend to adopt that in their mind because they only see that thing. Children work in a "monkey see - monkey do system", they imitate what they see and hear very much. That's how they learn to speak, walk, to care for animals, to love, to have compassion etc. by learning it from other humans.

When that lacks and all they see is the other side of life, their mind perceives it as normal. Later on when they meet the "normal" side of life, they are in for a shock and feel a bit uncomfortable about it, just as we are with their life (that has violence, etc. in it) and they never really forget the past. That tends to make their decision making a bit screwed up, none of it being their fault as they perceive it as right to themselves.

Childhood is what makes us to react and perceive things the way we do. When you are a teenager, you tend to grow out of that and THEN start seeing things and understanding them, asking yourself questions etc. Adolescents and adults can make decisions and change, while as a child you don't really know how to.

That is why criminologists study behavior from that area of a person's life. That time is usually the time when we are taught how to be human and what is like to be human. If something gets screwed up, there's a big chance that even though you change, you can never forget, forgive or be completely unscarred.