Dear Hungary,
http://www.wired.com/2010/05/ff_nicholas_carr/all/Yes, it's 4 years old. Yes, I'm sure it has been disagreed with. But it's an example of what I had in mind. I know there is social-science and neuroscience research on both sides of the debate.
I notice you qualified your response by specifying "moderate" digital activities. Who would disagree, once that qualification is inserted? And who would disagree that immoderate activities are deleterious?
So the issue boils down to how much moderate and how much immoderate activity is going on by whom when and where. The devil, as always, is in the details.
My anecdotal evidence from 40 years of teaching is just that, anecdotal. But convincing, to me. College students are less analytical, less able to see behind the "form" that they encounter because they are used to having the whole, virtual reality instantly in their face. They are adept at pushing buttons to gain a result but less aware of what lies behind the vitual reality on the screen. The virtual is the real, to them.
Analogously, they are less, not more, capable of analyzing a paragraph of writing, a chapter in a book (whether E-Book or cellulose book doesn't matter). To them language, words are a whole package (icon), not put together with skill by a writer. As a result, they cannot pick out the main point in a paragraph or in a chapter. They can get an overall impression, the "gist" of the chapter. Or so they think. But often their "gist" is incorrect. They are much more susceptible to manipulation by propaganda, if it's skillfully enough presented "on screen."
To give another example: over the years I have noticed decreasing ability to know what individual words signify. On exams, when I specify, "two letters in one blank space" to try to help them do a matching problem, they will often misread it as "two letters in all blank spaces" or something like that. The "icon" world they live in permits one to get by with general impressions. So, when they read sentences in a paragraph or a chapter, the individual words, adverbs like "merely" which may be crucial in establishing the meaning of a sentence, tend to get skipped over as minor details. But of course then they fail to "get" the point of the sentence.
Of course, this might be as much the result of whole word reading methods rather than immoderate screen time. I'm not claiming scientific proof for this. I'm just saying that I have seen deleterious developments over time. Perhaps I attribute them to the wrong cause. Yes, I am aware that there are studies both defending and criticizing distracted "multi-tasking" and digital saturation.
That's all anecdotal. Blame it on generational bias, if necessary. Perhaps I'm just an old geezer out of touch with the rising generation, unable to see the wonderful new world that has come into being.
On the other hand, what if, in this case, the new trends are actually deleterious?? What if the newest is not better? It is possible for cultures to fall as well as rise, for trends to be deleterious as well as better and wonderfuller. Often the unintended negative effects do not appear until long after the initial positive effects have become ineradicably established in people's minds.
Finally, let me return to my main point in my initial comment: the article on which this thread is premised offers evidence that even high school students find stamps intrinsically interesting rather than boring, as you have claimed. This is confirmed by a number of SCF threads and comments from those who work with school stamp clubs on the elementary school level.
The authors of the article merely claimed that (1) students found stamps interesting (after initial, typical adolescent feigned disinterest) and that (2) this seemed to them to be an antidote to deleterious effects of (immoderate) digital activity.
Perhaps your disagreement is as much with the authors of the article, not me.