Hi Rob,
The horizontal members in the stud cavities are called fire blocking here, and generally (in some markets) they are not installed as long as the holes in the plates are filled with rock wool or some other material to act as a draftstopper (as per the fire code). The fireblocking was
standard in almost all houses I have worked in up through the 80's....sometime after that time it seems that the practice dropped off.
I hear and read all the comments about how things are built in the US, and my observation is that there is so much variety over the 50 states and for 300+ million people that it is impossible to generalize about anything. Some standard practices are very good, others are so-so, and some are mass-market driven crap. It is the latter stuff that ensures that we have good remodeling work to do.
Most of the TV shows that I have seen are insipid, and don't really reflect reality (I know that you know this). Some of the stuff I see on them makes me :mad2: .