Jealousy is such a powerful emotion that at least one study has characterized it as the third leading cause of non-accidental homicide in all cultures. Is it possible that this universal green-eyed monster evolved as a survival mechanism?
In a study published Wednesday in the journal Plos One, researchers at UC San Diego experimented with dogs to see whether they, like humans, were hard-wired for jealousy.
If so, the researchers suggested that human and canine jealousy might exist for similar "primordial" reasons.
Although many dog owners will attest to bouts of canine jealousy -- even evolutionary scientist Charles Darwin suspected that the creatures...