Conflicted theories about the different registers is generally culturally related, which I will talk about more in the ethnomusicology section. Knowing the science behind producing high and low sounds can be productive. However, there is danger if the vocal cords are artificially manipulated in efforts to expand the register. Expanding the range is a process that has to be done naturally, that is why technique is so important in identifying where the breaks in the register occur.
Bridging the registers without a distinguishable break is the desired outcome. Female singers who have powered their chest voice without strengthening the head voice at the same time, run into trouble whenever they try to access notes outside of the octave range they currently use. The female cannot force the chest voice beyond the natural breaks that occur in her register both ascending and descending.