- people talk at other people while the other people are on the phone. The talkers seem to forget that it is hard to carry on two conversations at once. It is actually more efficient for the person to finish the phone conversation, then deal with the person in front of them.
- the human brain cannot actually multitask (see this NPR article). This is why it is more efficient to let the talker finish the conversation before s/he deals with the person before him/her.
- personal computers did not become common until the 1980's. Gen X was the first generation to grow up with computers, followed by Gen Y and the Millennials. Human beings do not mutate as quickly as lab rats or fruit flies. Three generations of computer-using humans do not translate to brains born instantly capable of multitasking.
They also learn not to respect adults. Druckerman gives several examples in her book of American children who do not respect adults, from rude teenagers to younger children who bite and hit their parents. Interestingly enough, Peter Mayle frequently describes rude adult Parisians in his books, so the French child-rearing method is obviously not fool-proof.