It has been said that the fundamental adult skill is deferred gratification. Children who master this skill usually become successful adults, and those who don't, don't.
You'd be hard-pressed to discern this truth from any ad for any commercial product, since nearly everything is marketed on the basis of promising immediate gratification. "There's an app for that!"TM means "more instant gratification for you."
Instant gratification is, indeed, gratifying, but only for an instant, in the same way that eating a potato chip is gratifying. It doesn't last, and there are consequences.
In the case of smartphones, texting, checking emails, IM'ing, and internet surfing, there are a few costs associated with the "convenience" and occasional pleasure of doing whatever you want whenever you want. This constant momentary checking taxes you in specific ways.
First, there are task-switching costs. When you switch from one mental activity to another, there is a loss. There is no such thing as "multitasking." It's just task-switching - when you multitask, tasks take more time and have higher error rates. Here's the research.
Second, seeking instant gratification actually makes you less happy: it impedes development of fulfillment and associated feelings of satisfaction and well-being. Fulfillment shows up when we have "flow," a term first identified by Mihalyi Csikszentmihalyi as an experience of total engagement. Flow occurs when we are so immersed in something that we don't notice the passage of time. Csikszentmihalyi explained that we can find flow by "doing great things, or doing everyday things with greatness." The ingredients to flow are: (1) a high challenge; (2) skills matched to the challenge; and (3) constant feedback. One of his findings is that people find more flow - and therefore more fulfillment - in work, rather than in leisure. This is because work requires us to engage. Instant gratification is pretty much the opposite of engagement. Flow comes from challenge, not ease.
Third, instant gratification is the opposite of mindfulness, which you might say is the one requirement for being content in life. Mindfulness means being present - living, experiencing and relishing the present moment, rather than being distracted by other thoughts or feelings. Mindfulness involves observing how the mind acts - when it gets bored, distracted, annoyed, fearful, etc - and is based on the idea that the mind is not you. It's part of you, but it's not the whole you. It's the tool, not the master. Buddhism calls the urge to get out of the moment, to move to something else, whether good or bad, "The Monkey Mind." The Monkey Mind is endlessly dissatisfied. When you're having dinner with a friend or loved one and decide you need to check your phone, that's the Monkey Mind in action.
Smartphones and their ilk are basically The Monkey Mind in physical form. With their constant ringing, buzzing and urges to "check me! check me! check me!" they are a ceaseless force urging you to leave the present moment and do something else. Your urge to check your smartphone feels like your real mind, but it's really your Monkey MInd. The false message of the smartphone is: "whatever reality you're experiencing now is not as good as the reality I'm promising you." So in addition to your natural Monkey Mind, when you carry around and are a servant to your smartphone, you have created a second, outsourced Monkey Mind.
Feel like slipping out of the moment and checking your device? Gawker will just have another snarky, celebrity story, similar to a hundred others you've read. Facebook will have some updates, but nothing as real as the reality you're in. That email might be good or bad, but it's just another email.
Just as that additional potato chip is not really going to make you happier. Just fatter, and experiencing a salty aftertaste. And setting up the urge to do it again in 30 seconds.