Brain activity scans on trauma survivors who disassociate show how events can be trapped in the emotional phase and never reach the thought stage. If the trauma event cannot escape emotion to logic, the individual essentially stops maturing until the original trauma can be felt and processed fully.
Studies in rats even show that this trauma can be passed down genetically to offspring next generation.
These two were engaging in highly emotional traumatic activity very similar to what you'd expect in immature children. It's a cycle and if you can't understand it, I'm happy for you.