New research out of Arizona State University has determined the exact age puppies reach their maximum cuteness to humans. It turns out this is the exact time their mother is trying to get them to leave the den. Puppies are most appealing to humans at 6 to 8 weeks of age. Which is also the time they are being weaned from their mothers. This is perfect timing because that's when they need a human to start taking care of them.
The study was based on a survey of 51 humans who were asked to rate various pictures of puppies at different ages. For all the breeds in the survey cuteness reached its maximum level before 10 weeks old.
Of course, we don't stop loving them after they're 8 weeks old. It's just when the "hook" is the biggest. My dog Maddie has been cute since the day we got her. The proof is in the pictures!
Source: CBS News