Friendship: The Evolution, Biology, and Extraordinary Power of Life’s Fundamental Bond

Science writer Denworth takes a broad look at the origins and functions of friendship in her intriguing debut. Her focus ranges from animal behavior to neurobiology and from sociology to psychology and physiology. After speaking with many leading researchers, Denworth draws several striking conclusions—notably that, having been found in an extensive variety of species, friendship has deep evolutionary roots. This helps explain the large panoply of positive health benefits associated with friendship and, inversely, the dire medical consequences she reports as sometimes arising from loneliness. Denworth also examines the impact of virtual relationships and the increased use of technology by different generations, concluding that research demonstrates no net benefit or harm from social media use: “Friendship, real friendship, hasn’t changed much. It is alive and well, even thriving.” Her reporting is peppered with personal asides about how she and her family members have navigated various relationships. While this enlivens her work’s more technical facets, it does potentially give the impression of putting anecdotal experiences on a par with evidence-based studies, thus undercutting the importance of the latter. Science enthusiasts may find Denworth’s survey wider than it is deep, but it does provide an effective introduction to its subject. (Feb.)