This might be construed as sloppy research.
I tend to agree, but like to qualify that. The two papers are different in both approach and goal. The Chang paper is a straightforward investigation of a simple observation and related hypotheses. It is performed by anatomists collecting a sizeable number of specimens, taking and correlating relevant measurements, and discussing possible confounds and previous findings. The conclusion makes sense, but isn't necessarily the whole story nor does it purport to be.
The Gallup study is more of a broad-based functional explanation of a phenomenon by (evolutionary) psychologists, based on observations essentially made by others. The fact that the Chang paper isn't mentioned may be seen as sloppy (and this would apply to the peer reviewers as well), but it doesn't detract from the thesis proposed as I outlined above. The fact that their conclusion is based on a literature review contributes to the 'deja vu' effect I experienced. This is unfortunate for the authors, as their conclusion may not have been forwarded by others in this particular form.
Pointing out that these two papers were written by anatomists and psychologists respectively wasn't meant to introduce a bias regarding one or the other, but to suggest a different point of view and potentially different methods etc. Looking at data from different perspectives has a long history of producing novel and valuable insights between distracting bouts of painful drivel. The chance of the latter should not stop anyone from thinking outside the box but neither should they wield their ridicule prematurely.
