For some children (and probably some adults you know as well), the window of tolerance is very small. Bringing the light of awareness to that unconscious place is where healing and integration can take place. Everyone has a window of tolerance. and yes, size in this case does matter. Not as in good or bad, but as in "we can relax, it will be ok" or "oh oh, we better pay attention or this will get out of control". This is not something to shame, blame or punish in order to change. When the window of tolerance closes, dysregulation begins. It is a brain thing. And yes, you can, with some work, expand your window of tolerance, and so can your child.
We have called the brain lazy, but that is just a metaphor. Really, the brain is very economical. Our neurons, like water, take the path of least resistance. "It" doesn't know any better. If "it" did, I assure you it would take the higher or better path. "We" need to step in, to do things differently, to "change" so that our brain's neuronal synapses and processes change. How? Love really can change things. Love triggers processes in the brain that in effect let everyone involved know that everything will be ok. We can all relax.
This applies equally to children as to adults, except that children need someone to help them with this. Keep in mind that the brain doesn't fully develop in most people until around age 25. So yes, relax. Everything will be ok. As a wise woman once said, "everything works out in the end, and if it hasn't, it's not the end".
Choose Love -- David Durovy