Add Yahoo as a preferred source to see more of our stories on Google. Guest Opinion. Altruism is helping without a benefit and sometimes at a risk to one’s self. Animals helping others of their own ...

People of all ages rely on their pets for a serotonin boost, whether they’re throwing a ball for their dog, petting their cat or talking to their fish after a long day. Nancy Edwards, professor and ...

Of the 8.7 million species on Earth, why are human beings the only one that paints self-portraits, walks on the Moon and ...

Sign up for CNN’s Sleep, But Better newsletter series. Our seven-part guide has helpful hints to achieve better sleep. Max Genecov is a doctoral candidate in ...

Keller Kopf does research on long-lived animals and has received grants associated with the management and conservation of fisheries and wildlife. In humans and other animals, ageing is generally ...

Eli Elster does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their ...