  Software engineering is a highly dynamic discipline. Hence, as times change,
so too might our beliefs about core processes in this field. This paper checks
some five beliefs that originated in the past decades that comment on the
relationships between (i) developer productivity; (ii) software quality and
(iii) years of developer experience. Using data collected from 1,356 developers
in the period 1995 to 2006, we found support for only one of the five beliefs
titled "Quality entails productivity". We found no clear support for four other
beliefs based on programming languages and software developers. However, from
the sporadic evidence of the four other beliefs we learned that a narrow scope
could delude practitioners in misinterpreting certain effects to hold in their
day to day work. Lastly, through an aggregated view of assessing the five
beliefs, we find programming languages act as a confounding factor for
developer productivity and software quality. Thus the overall message of this
work is that it is both important and possible to revisit old beliefs in SE.
Researchers and practitioners should routinely retest old beliefs.
