New research reveals that infants just five days old can tell the difference between two distinct forms of prosocial and antisocial behaviour—and they prefer the prosocial. This suggests that some parts of how humans understand and evaluate the social world may be built into the brain from birth. Researchers showed a total of 90 newborns sets of simple animated videos. In one, a ball struggled to climb a hill. Another ball helped push it up. In a second video, playing right next to the first, the second ball pushed the climber down the hill, preventing it from reaching the top. Infants’ eyes lingered longer on the helping scenario. In another set of videos, one ball moved toward another as if trying to get close or say hello. In the other video, the ball moved away, like it was avoiding the other. Again, the newborns spent more time watching the friendly, approaching action.

The evolutionary path from dinosaurs to birds included the development of a tiny wrist bone that ultimately proved crucial for stabilizing wings in flight. A new study suggests that the bone appeared in bird ancestors millions of years earlier than first thought.

Paleontologists at Yale and Stony Brook University led a research team that made the discovery after examining fossils from two species of bird-like dinosaurs — an unnamed troodontid and a Citipati from the Late Cretaceous period 66 to 100 million years ago — found in the Gobi Desert in Mongolia. The findings were published in the journal Nature.