Why are teenagers moody?

Answer 1

There is quite a lot going on in the brain of a teenager (or preteen) including a growth spurt in synapses, growth of the myelin sheath and changes in hormone levels. Additionally, teens are beginning to feel more adult and tend to resent what they see as "control" by others in their lives.

Answer 2

Teenage boys become aggressive and competitive; they appear to rebel against authority, but actually are just responding to their own hormones that tell them that it's time to get out in the world and be independent, it's time to select a companion and start a family. Without those nudges from the hormones, why would anyone in their right mind ever want to leave the comfort and relative security of their parents' home?

Male hormones are a little more clear than female hormones.

Female hormones dictate that the female bond with the other females of the clan and reject the females of their former clan. They too are seeking a companion with whom they can start a family of their own, but they are more focused on other parts of a relationship.

And the problem is, it's not universal for everyone and not even possible for us to identify when it's happening inside our own bodies and minds.

Teenage girls are "moody", because of the changes that are constantly occurring and because they tend to see social cues that teenage boys typically miss completely.

For both the boys and the girls, modern life is frustrating because at a time that the body is telling them to be independent, the intellect is telling them that the modern world is far too complex to leave the security of their parents' home.

Answer 3

Because they are going through changes and they act out mainly to get attention. They want you to be there for them.