Steve Zolotow, in his column for Card Player magazine, June 13, 2012, writes this (page 40):
I hope everyone avoids looking at their cards until it is their turn to act. There are two reasons for this. First, you can't reveal anything about your hand because you don't know it yet. Second, you can focus on your opponents and not on your cards.
I have, of course, heard this argument before--many times, in fact. When I was first learning about poker by watching television shows like World Poker Tour and Celebrity Poker Showdown, I specifically remember hearing both Phil Gordon and Annie Duke explain that looking at one's cards before it is one's turn is an amateurish mistake.
I understand perfectly well the arguments made in favor of waiting to look. But what advocates of this position usually omit, or perhaps do not grasp, is that there are countervailing arguments.
First, waiting to look until it's your turn means that the whole game runs more slowly. That is not a small consideration.
Second, to quote Phil Ivey, "If you have tells, work on them." If you're giving away information by body language or facial expressions when you check your hole cards, that's a problem you need to fix pronto. Whether you give off that information a few seconds after you get your cards or only when it's your turn makes little difference. You need to not be spewing such tells, period. Of course it is the case that your action (fold, call, or raise) will also be giving off information, but that is a separate matter. You don't want your face and body to be saying one thing and your bet a contradictory thing.
Third, if you wait to look until it's your turn, all eyes will be on you as you do so, because everybody is waiting for you to act. Thus, if you do have tells, the way to be sure they get maximal attention from opponents is to wait until everybody is watching you while you check your hole cards. On the other hand, if you do it when most other players are doing it--as they receive their last down card--they're all busy with their eyes elsewhere.
Fourth, if you wait until it's your turn, you're likely to give off information by how long it takes you to decide what to do after looking at your cards. Raise or not? If so, how much? Even if your face reveals nothing, the delay in action can suggest how complicated or difficult your decision is. I say let that decisional time pass while other things are going on.
I don't usually like appeals to authority in argument, but it is definitely not the case that all the best players in the world wait to look until it is their turn to act. These days we are getting more and more live broadcasts of late stages of big poker tournaments. Just watch--you'll see that there is a lot of variation on this point among the greats. Though T.J. Cloutier seems to be pretty much vanishing from the tournament scene now that he is, sadly, in the twilight of his life, I clearly remember him addressing this controversy in one of his books. He said that he likes to give a quick glance at his cards as soon as they arrive, then direct his attention at what how the other players are reacting to theirs. I agree with him. It takes literally one second or less, so you won't be missing much.
I like having my own cards in mind as I watch the other players act. Often my default decision about what to do changes. A completely crap hand becomes raiseworthy if I'm in late position and everybody has folded. Marginal hands like A-8 and Q-J can go from being planned raises to being folds if there is any action before it gets to me, or reraises if a raise comes from a habitually frisky player. And so forth. I would be stunned beyond belief if any of my opponents can read on my face these changes in my thinking as the action unfolds.
For what it's worth, I've noticed that Cardgrrl adopts a compromise position. She looks at her cards when the action is about two seats to her right. There is an argument to be made that this tactic incorporates some of the advantages of both of the more common approaches (looking immediately, or not until it's your turn). It's worth considering.
I don't mind that there are differences of opinion, preference, and style on this question. What bugs me, though, is how dogmatic many proponents of the Zolotow/Gordon/Duke position are about it--insisting that theirs is the only right way and any deviation from it is a clear error. I just don't buy it.