"I would like to know if it is a good thing to call a child dumb when you see a 6 year old child not using his thinking skills or when he is not paying attention while playing a game. My husband gets so irritated when he sees our daughter not playing "intelligently" and says things like "Are you dumb?" I don't want to play with dumb people....so on and so forth.
Let me know what you think of this.."
I think your husband is acting out of frustration and talking to your daughter the way he was talked to, but that it's going to have an entirely different result that he hopes it will.
If you tell a child something repeatedly, s/he is going to start believing it. So if he keeps telling your daughter that she's dumb, she's going to start thinking she's dumb. It's a pretty simple equation. Kids love us so much that they believe everything we say, so if he tells her that she's dumb she's going to internalize it and think it's true, no matter what other people say. (And then when she's grown up and has spent thousands of dollars in therapy to get over her feelings of being dumb, she's going to resent your husband and be filled with anger at him. So it's a lose-lose situation for everyone but the therapist.)
The other thing to consider is that your daughter is going to start talking to the two of you in a sarcastic and demeaning way if that's how she's talked to. If that doesn't make you want to snap, I don't know what will.
I completely understand your husband's frustration. When a kid who's normally smart just does dumb things again and again it makes you a little nuts. But if the goal is to get the kid to start using the old noggin a little more, then positive reminders are a better way to go. Instead of "Are you dumb?" he could try "You're not playing as well as you usually do. What can we do to help you pay better attention to the game so you can really think about your moves?" Instead of "I don't want to play with dumb people," he could try, "I feel like you're not paying attention right now. Should we go read a book instead?"
These alternate ways of talking to your daughter do two good things. The first is that they don't stick her with a label. Labels, good or bad, are damaging to kids because kids feel they have to live up to that label at all times. (For a full explanation of how even "positive" labels can backfire and make kids feel bad about themselves and act out, read Between Parent and Child by Haim Ginott.) The second is that it takes the focus off being smart or dumb (because face it, all of us have our dumb days) and puts it on paying attention to the game and teaching your daughter to either focus on the activity at hand or cut bait and move on to something else she's more interested in. Learning how to regulate your own attention and focus is an enormously valuable skill.
The bottom line is that your husband is the adult, so he needs to curb his sarcasm and frustration and act like the adult. If he can't control his temper, you could always approach him by saying, "You're usually so patient with our daughter, but it seems like you're really frustrated tonight. What can we do to help you speak to her in an appropriate way?" (If he gets mad and thinks you're patronizing him, blame me.) And then make sure that the two of you make a conscious effort not to talk about yourselves negatively in front of your daughter, either, so she doesn't start to think her parents are bad or incompetent.