However, this is a topic I'm very interested in because my fiancee is the first person I've ever met that does not reply back soon to a text message and hardly picks up her phone.
When we first started dating, this was a little strange. She would sometimes reply back within minutes. Other times she would take up to two hours. I couldn't gauge her interest in me.
It turns out due to her age and culture (non-Western), she just simply does not use her phone that much. So she isn't looking at it a lot.
We've argued that there must be a middle ground, though, and this is where it gets interesting.
This isn't really a technology problem. It is a philosophical one.
When we deal with people everyday, there is an unwritten and unspoken social contract we agree on. The case for not replying immediately to a stranger or an acquaintance is easily accepted, I believe. As the article says, you may be driving, you may be in another phone call, busy reading or studying. A stranger or acquaintance takes a longer time to sit higher up in your priority list. This is a basic socialization rule. I accept these things easily, and what's more, I act according to this concept. I basically categorise people's importance in my world. Even if I've read the text message, seen the missed phone call, or read the email. These categories are key, I believe.
However, when a loved one, your significant other, spouse, fiancee or fiance, messages you or phones you or emails you, it is a totally different ball game, in my view. Emergency purposes, communicating your whereabouts sooner makes cohabitation much easier, especially when planning your day, unexpected plans, people know your schedule/routine and any changes may cause grief to your loved ones, etc.
I do feel like family whom you do not live with is considered a step down in the priority list, but those you live with, specifically a partner, is different. And feeling insulted when they don't respond within 30 minutes at most generally, is pretty natural.