"But stuttering is definitely neurodevelopmental+psychological otherwise you can't explain away the first time when PWS stutter, and no need to explain why it is also psychological." Regarding your comment about early onset. If stutterers often start between the age of two and five, when they start to learn to speak, then toddlers will of course bobbulate because they are learning the habit of speaking (it's not a habit yet). Speaking isn't something we are born with, speaking is a skill that we learn and at the age of 2-5 years old, we are not perfect speakers and therefore we have influent speech. Then the chance of bobbulating will increase if someone has anxiety (for example, bad experience) and a kid doesn't have a high vocab so instead of solving his anxiety by reasoning, he will create strong emotions and connect it to speech (creating a stutter feeling where he believes it results in a stutter). 80% of kids outgrow stuttering. However, the 20% that continue stuttering might be under habit forming: \- believing he cannot stop compulsion (freezing speech) \- believing he cannot make progress \- reinforcing a stutter habit \- creating a condition that he needs a technique (and coping strategies) because without it he 'would' not be able to control his speech \- reinforcing anticipation of a stutter (learning to see a stutter coming in order to prepare for it like changing words, avoidance) \- reinforcing his belief that the stutter trigger is real \- reinforcing unnatural speech \- deliberately focusing on speech mechanism in order to control speech muscles (instead of letting go where one puts faith in his body to automatically stop compulsion) This then results in neoplastic adaptations.