Photo: Dr. Jane Goodall In this photo, which Dr. Jane took, you can see chimpanzees engaged in grooming — behaviour that ...

Chimpanzees and bonobos maintain tight inner circles of preferred grooming partners inside their wider social networks, mirroring the layered friendship structures that scientists long assumed were ...

Female chimpanzees that forge strong, grooming-rich friendships with other females dramatically boost their infants’ odds of making it past the perilous first year—no kin required. Three decades of ...