[Jach]

Extraversion has had proper studies with the Big 5 traits, it's more than just "talkativeness". But some of the seeming conflicts come from the 5 traits being able to be factored further into 10 aspects; for extraversion it splits between "enthusiasm" and "assertiveness". See e.g. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4818974/ or http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.513...