Children and teenagers often lack the ability to gauge how their words affect others, leading to socially awkward or hurtful comments. They might not notice when their tone or bluntness causes discomfort because they haven’t fully developed social awareness and self-regulation skills. Despite their good intentions, their lack of a “social filter” can create issues. Simply telling them to think before speaking may not be effective; they need guidance and support from parents to improve their social skills and understanding.
https://www.yourtango.com/family/how-teach-outspoken-child-show-respect