Six-month-old babies can understand the difference in dog barks even if they’ve never been exposed to dogs before. A new study from Brigham Young University shows infants are able to match the sounds of an angry dog with the appropriate picture of a dog with an aggressive posture, and a friendly yap with a friendly posture. “They only had one trial because we didn’t want them to learn it on the fly and figure it out,” said Ross Flom, lead author of the study. The study shows that babies are capable of recognizing feelings around them and will help researchers understand how babies learn so quickly. (Babies can also pick up on shifts in moods in the music of Beethoven.) “Emotion is one of the first things babies pick up on in their social world,” says Flom.