A 2009 study found that dogs have the intelligence of a two-and-a-half-year-old child. They can also understand up to 250 words and gestures. And they've had a long time to get it right. We started domesticating dogs 10,000 to 15,000 years ago, and that domestication runs deep. It turns out, even dogs who have never heard a human yell "roll over" might still understand basic commands. A new study found that stray dogs can understand human gestures, such as pointing, which suggests that dogs innately understand people.

Dr. Anindita Bhadra of the Indian Institute of Science Education and Research Kolkata and her colleagues studied 160 stray dogs across several cities in India. Two covered bowls were placed in front of each dog. One bowl contained raw chicken, and the other bowl was both empty and food-scented.