Anonymous wrote:OP here. Thank you for the thoughtful comments. As background, we (family with young child) have spent time with them for weeks at a time to visit. The tantrums happened daily (multiple times), over things like having ice in a cup, his sister brushing too close to him, etc. They were loud and stressed out the parents, who would have to take him outside or into another room until he calmed down. The parents have mentioned the behavior so it happens routinely (not just on vacation). He starts pre-school this year so we will see if others mention it; he was previously with a stay-at-home parent. Thus far, I have not said anything, just listened. I would like to see them get the support that they need so they can all be happier.
This is normal. It’s why adhd isn’t diagnosed at 3yo because many at this age do this stuff. Ignoring it is the best approach. Even negative attention reinforces it. Stress reinforces it.