The child-king syndrome is a Hydran sickness characterized by egocentrism, caprices and they would be described among Federation and Romulan scientists as "spolied brats". Also, Hydran science described the most likely causes of the child-king syndrome as being the result of under-disciplining the child and of continuous pampering of the child.
Children afflicted by the child-king syndrome onboard the HMS Sovereign killed all grownups onboard and opened hellbore cannon fire on the RIS Bouteina as part of their caprices.(RIS Bouteina: "Spoiled Rotten")
The child-king syndrome camt to the author's light by a French-language psychology book whose subject was the enfants-rois, who exhibited the same traits as the Hydran kids portrayed in Spoiled Rotten. It also appeared to be a mistranslation from Cantonese or Mandarin of a term that would be better termed "Little Emperor Syndrome".