The stuttering is caused by mis-timing / desynchronisation of neurotransmitter signals in the speech motor areas of the brain (basal ganglia, striatum, Broca’s area etc). By slowing down, breathing and using other fluency shaping techniques we are essentially trying to calm and re-sync the speech motor networks for a more controlled speech pattern. At its core though, it’ll always be there. We just use fluency shaping strategies to minimise blocks/stammers.