Cats or dogs -- which are smarter?

Science magazine reignites an ages-old debate with the results of a published study that concludes dogs' brains have twice the amount of neurons as those of cats. That means dogs are likely twice as smart as cats.

Researchers from six universities living in four different countries all contributed to the study and its findings.

Because neurons are the basic information processing units in the brains, the more anyone has, the more they are able to comprehend.