We all know—well, we should have heard of it by now—that the world looks different to those whose glasses are half full, as opposed to those whose glasses are half-empty. Whether the attribute is determined by genes or environment, or maybe both—or whether the question makes any sense!—is beside the point; we're not looking at causes right now, but only at consequences.
The essence of 'positive' attitude isn't blind "everything is good" or "I can do anything" or shit like that, but of "these are the cards; and I'll be damned if I'm not going to play them for all they're worth". And it now appears that people who look at the world with a what amounts to a 'positive' attitude, in the sense just explained, actually see more than those who don't. Literally. We're talking about visual perception!
"...when in a positive mood, our visual cortex takes in more information, while negative moods result in tunnel vision..."
Of course, there's a downside as well:
"Good moods enhance the literal size of the window through which we see the world. The upside of this is that we can see things from a more global, or integrative perspective. The downside is that this can lead to distraction on critical tasks that require narrow focus, such as operating dangerous machinery or airport screening of passenger baggage. Bad moods, on the other hand, may keep us more narrowly focused, preventing us from integrating information outside of our direct attentional focus."
So, as usual, it's a question of balance and what you might call 'contextual appropriateness'. Well, I call it that.
And here's something else interesting...
One of the most recognizable facial expressions is disgust: the expression displayed by an individual who is exposed to a nauseating image or horrifying story. But what happens when this emotion is not expressed? When the person keeps a straight face – either intentionally or unintentionally – and pretends that nothing is wrong?...
...[People who are disgusted by something and who don't show it] experience more negative emotions. ‘They look at the world with negative eyes because they cannot get rid of their feelings of disgust by expressing them. A botox treatment also has an effect on emotional experience, therefore, and not on wrinkles alone’.
An unexpected side-effect of botox, it seems. Wrinkle free-ness appears to come at a high price; not just financially.
I advise perusal of the article in question. It offers a lot of food for thought, beyond that about mere facial twitches. And it's not long; short enough for even the ADD generation.
And as if that weren't enough—such things seem to come together—there's anther aspects to disgust, or, to be more precise, our inclination to be disgusted. In a classic bit of evolutionary negligence, it appears that, as one would expect, what once used to be a protective mechanism against disease—see something icky and stay away from it, because if you touched it, you got ill and possibly dies of some horrible disease before you had a chance to propagate your genes!—has turned into something that influences our ethical and moral assessments of the world as well.
Not only decaying bodies with maggots all over them are icky, but so are certain things that people do—and I'm not just talking about a certain drunken Australian rugby player (or whatever you call the variant of the sport the offender practiced; I know nothing about that stuff and really don't give a rat's behind about the nuances of these wally 'sports') defecating on in the corridors of hotels—but about moral judgments about everything from gay practices to abortion and so on. Indeed, the ultra-conservative, anti-immortalist, religioid (now there's a bunch of insults that should shake any man in his boots!) 'ethicist' Leon Kass—whom Wikpedia, without any editorial provisos described as a 'public intellectual'; which is an insult to intellectuals, no matter how little I think of the breed in general!—promoted a notion called something like 'the wisdom of disgust'; thus trying to justify its use in moral judgments.
As usual, we find that, on one hand, it is really important, for our mental health and that of the societies we create, to yield to the need to allow our evolutionary heritage to find some sort of expression—just say "YUCK!" when it seems appropriate and you really, really want to—but also to ensure that we don't become slaves to said heritage.
We live on a brink of what we are and what we can be. It's a very thin ledge, and the winds are blowing this way and that, and it's so easy to fall this way or that.
I know it's hard, but we have to keep on trying to our last breath, not to allow ourselves to fall.
The existential joke life has played on the likes of Leon Kass is that, while they think that humans—and they themselves, of course; especially they!—are the pinnacle of creation and the best-possible-image of some monomaniacal God, the belief that an evolutionary survival tool like disgust has any value at all beyond what it happened to have to a bunch of primitives who had no clue about the realities of microbiology, negates everything they'd like to claim about their own superior intellectual and existential status in the world.
The joke is on them. The whole damn joke. The rest of us just have to make sure that their primitive ways of thinking—did I say 'thinking'?—don't drag us back to the times when these things still had survival value.