Like AliceD's answer says, this is a form of forced-choice task used to assay preferences.
These measures are used especially when there is no good counterpart on the opposite side: there is no spectrum to consider. Let's think about your examples:
In general, I prefer [Assertiveness / Clear communication]
I prefer my direct reports to be [Self-...
You have answered your own question:
...tests that force one to choose...
Such tests are generally referred to as forced-choice tests in psychophysics. There are many applications of these tests. In general, AFC tasks are less biased than for example yes/no tasks (Yushurun et al, 2008). A sample paper on an ...