Its more of a touch screen question than an Android question, but it pertains to an Android device so... I got my Dad an Acer A510 for Christmas and he has been very frustrated with it, especially the touch screen. I noticed that when he taps the screen it does not respond as readily as when I tap it. So my question is: do touch screens not respond as well to older (drier) fingers? He lives in New Mexico, and probably has relatively dry skin. Alternatively, is he just doing it wrong and skin type has nothing to do with it?
It may be that he's used to older resistive touchscreens (the kind you use with a pointy stylus), and so he's pressing the screen with the tip of the fingernail, instead of with the finger itself. That doesn't work well on capacitive touchscreens unless your fingernails are cut very short.
Also, you're probably right about older, drier fingers having less capacitance and so showing up less well on the screen. Using the 'pad' of the finger instead of the tip might help by giving the screen more finger to work with.
If all else fails, you can get styli for capacitive touchscreens. You can distinguish them by having a rounded, foam tip the size of a finger, instead of a pointed, pen-like tip.