"The cranial anatomy of Ateles is notable for what it does not display. The narrow facial skeleton is relatively shallow, gracile and unremarkable, in keeping with the general expectations of a highly frugivorous taxon. The braincase is also relatively simple in design, rounded as might be expected in a modestly encephalized form. This simplistic picture is not meant, however, to imply that the Ateles head is also primitive in design. On the contrary - it combines a variety of traits not expected in the ancestral morphotype of atelins or atelines..." (Spider Monkeys; Behavior, Ecology and Evolution of the Genus Ateles, ed Christina J. Campbell, 2008)
Translation? Lolita has a good head on her shoulders. But we already knew that.