Children might say that someone who disagrees with them is wrong, and further that they should cease to believe that wrong thing and instead believe what the child thinks is correct.
This is often attributed to arrogance; the child thinks that what they have learned is true, and is not open minded enough to consider that they may be wrong. When this is the case, it is perhaps excessive to call this arrogance, as the child likely does not know any batter, might not know about subjectivity, and might not have been taught how to be open minded.
While this is possible, there is an alternative explanation. As mentioned before, the child is not necessarily aware of the concept of subjective truths, especially with regards to tastes and preferences, which is a concept that needs to be taught to them. Instead, they understand truth as objective, which in my opinion is at least better than believing that all truth is relative and subjective. Along these primitive lines though, it is natural for them to not understand that interpretation and bias affect your understanding of the truth. When the child believes that something is true, it is therefore rational for them, and (counterintuitively) in fact considerate, for them to want to correct others who hold what they think is an incorrect view. In such a case, it is not a matter of the child wanting to be correct, or of them wanting or needing everything they think to be correct, it is a matter of fixing what they see as someone else who has factually wrong information.
The reason I claim this is considerate, is that in this situation, contrary to the situation in which they are being arrogant, their goal is not to show that they are correct, or to reassure themselves that they are correct instead of an opposing theory, it is to correct the easily corrected mistake of someone having wrong information. This is no different from an adult politely correcting someone who made a false claim, however one would hope that an adult doing this would be more certain that they are correct. In a way, a child doing this is more so concerned about other people making mistakes, or simply concerned that there is false information that has yet to be corrected. It is in fact disrespectful and negligent to willfully let someone believe something incorrect. If an engineer sees that one of their peers has made an error in their calculations but does not inform them of it, their peer may continue to build something based on that faulty information, which may cause it to fail, which could result in a fatal accident. it could even be something as simple as someone thinking that the current day is friday when it is in fact Thursday. If you know that they are mistaken and choose not to tell them, they may not go to work or class the next day, which may get them in trouble. This is in fact an indirect form of deception, as you have the choice to let this person know the truth or believe something false, and to help them avoid a mistake or to let them continue and make it.
Of course this argument depends on you, or the child, actually knowing the truth. If you are wrong and you try to correct them, you will actually be doing the opposite of what you are hoping to do. If someone claims the current day is Friday and you honestly think that it is Thursday, then when you try to correct the other person’s supposed mistake you will have created the problem you were trying to avoid, and that person might miss work because of your premature intervention. It also depends on the matter being objective, since it is not possible to correct someone on subjective matters as they have no correct response.
Rather than insisting that someone is wrong, the child should instead inform the person that they do not agree, so that at the very least they can consider each other’s opposing views. This way they can discuss it or research the matter to determine who is correct and how to reconcile the two views. In this situation you are able to help others and promote the truth, while avoiding risks of misinformation. Knowing more true things and fewer false things is always better, so being willing to start the dialogue and express doubt is an important part to that. Unlike a child claiming they are correct, expressing doubt is not arrogant.
While this explanation does not apply to everyone, and is just an explanation, it is better to not generalise everyone that does this as simply being arrogant.