Dog

You already know dogs are loyal, trainable, and good company. What you probably don't know is the depth of the cognitive and neurological bond they've evolved specifically for reading humans — a bond so finely tuned it took tens of thousands of years to build, and one that is genuinely unique in the animal kingdom.

Facts you didn't know

• 1

  Dogs can smell disease. Trained dogs have detected cancer with over 97% accuracy from breath and urine samples — outperforming some standard medical tests. They can also detect low blood sugar in diabetics before any symptoms appear.

• 2

  Dogs tell time using their nose. A human's unique scent fades and disperses throughout the day; dogs detect how concentrated your smell is at the door and use this to estimate how long you've been gone. This is why they often greet you differently after 30 minutes versus 8 hours.

• 3

  Dogs have a 'left gaze bias' when reading human faces — they focus on the right side of a human face, which is more emotionally expressive, exactly as humans do. They do this specifically for human faces, not objects or other dogs.

• 4

  When a dog looks at you, both of you experience an oxytocin surge identical to the one between human parents and infants. The neurochemistry of the dog-human bond is indistinguishable from parental love.

• 5

  Dogs are one of the only non-human animals that can follow a human pointing gesture without training — a form of social intelligence that even our closest relatives, chimpanzees, require extensive training to develop.