So, drilling down further into the physiology of the brain, Mr. Dunbar's team has now found that a rich social network also goes with the ability to reason about others' intentional states.

WSJ: The Social Network and the Dunbar Number | Mind & Matter

Since much is still not fully understood about this art and its sources, the exhibition and catalog are replete with fascinating speculations rather than traditional iconographic interpretations negotiating a terrain that touches on cultural anthropology, the history of technology, and brain physiology.

WSJ: Artistry, Not Answers | Ice Age Art: Arrival of the Modern Mind | British Museum | By Tom L. Freudenheim