I agree with many of your comments.

It often happens in developed and developing countries.

Children grow up, leave home to go to school or to get a job, and the family unit is broken.

The family that used to grow up, go to school, work, marry, and live in the same town made it easy to keep close famial ties.

So, now we must learn to keep ourselves engaged, active and happy.

Sometimes, the old ways really are the best ways.

Interesting discussion Laura.

Change your view to this world , world will automatically change . 

Stay happy, spread Happiness ^_^

Thank you everybody for your interesting thoughts.

Ciaobabe: I also think an attitude can be spread and it is important to try to be as positive as possible.

Allen: I think we are born with a particular personality (character / temper) and throughout life and experiences we might modify it. I think when we are born we are "survivals" and we need other people's attention to live. As you said, our society encourages selfishness.

Karen: I agree with you when you describe how many children were grown up (thinking they were the "belly" of the world) and it could be this attitude what have made actual adults more selfish. 

Jackie: It is true that society has changed and at least there, the fact that women are working out of home made a big difference but sometimes it is not about spending time with someone or doing something, it is about thinking of people: a phone call to someone who needs it, a lunch once a month with that person, a smile to that person who's not having a good time...

Richard: When people grow up and they become adults they start a new family so it is understandable that they are not that close to their parents/brothers/sisters but the fact that I am starting a new family doesn't mean I have to break my "ties" with my original one (parents). I feel selfishness is everywhere, not just in families (also at work) and in general I think we are becoming so much individual that we are losing "the others".