Taking a child expressing (clumsily; they're learning) their emotional reaction to something you say/do as "attitude" or "talking back," getting upset about it (ego) and then coming down overly hard (only making things worse).
For example, you tell your five year old that they need to finish their dinner before they can watch TV. They respond by telling you that you're "mean." You then get angry and come down on them (*how dare you speak to me that way* type of response, often followed by a threat or punishment).
A better response would be taking the time to explain your rationale for making them eat first before TV.
Kids need to know there's a beneficial reason for us stopping them from doing things otherwise they take it as nothing but authoritarian dominance and that sort of perceived dynamic never ends well.
I know we're often frustrated or tired and no one is perfect but trying to minimize this sort of thing is better for both parties in both the short and long term.