|Photo by Ruth Shiroma Foster|
Interesting question. Let me ramble, as I don't know exactly how I'll answer your question just yet. At a very core level, all humans want to thrive (survive, grow). Our human nature is to have imagination - imagination being the advanced evolutionary trait that allows us to plan for the future. At the base level, imagination is tied directly to thriving, surviving. It is thus the level of complexity by which humans use imagination that allows them to apply their energy to larger, more conceptual, institutional endeavors that promote human thriving - "making the world a better place," if you will. The simpler use of imagination may be to consider the ramifications if a mother fed her baby potato chips only - imagining how doing so would destroy her child and imagining feeding the child fruits and vegetables will promote a healthy body in the future. Both desires and applications of imagination, it can be argued, are inherently selfish because they harken to that core desire for human thriving, survival. It's just that in the case of "making the world a better place," you are applying your desire to thrive several concentric circles outside yourself. I think the drive for why we do things needs to be examined.
I don't know if I can speak for my generation per se, but among my peers, it's clear that many are applying themselves in a way that they know they are "giving to the community" to make the world a better place. This trait is seen in ministers, park soccer league coaches, songwriters, bloggers. I don't know how self-aware they are as they do it, but at the very least, their contributions often serve large groups of people - the community. The inventors of Google are 40 (I'm 41), and I don't know their story enough to know whether they planned to make the world a better place. But the result of their complex imaginations made it so anyway - sort of like positive collateral damage.
Your observation about people your age living for themselves - perhaps their imagination goes only to the bounds it's ready to go - so to family and friends, but nowhere outside of that. I think that quality is mutable as people's perspectives change with life experience. I have a friend who is putting his money, leadership, talent and design skills toward having humans populate Mars one day - with the idea that Earth will one day be unable to sustain human life. Now that's applying his imagination many, many, many concentric circles outside himself. One of the reasons homo sapiens were able to survive while other species died out was its ability to create community and use shared imagination. I think among humans, there are those who can think conceptually and apply themselves in larger ways that affect the population at an institutional level. But, there are those who keep their interests pretty close to themselves, just enough for their own inner circle to support a more predictable path. I've come to the conclusion that both kinds are necessary for the advancement of humanity. You need the thinkers and leaders to create new curves, but you also need the everyday folks with perhaps less imagination to sustain the curve long enough for the next one to come about.
Not sure how satisfying this response is, but something to chew on.