Feel-good research
In a recent study published in "Proceedings of the National Academy of Sciences," participants' brains were monitored by MRI scans while they made decisions about donating part of their research payments to charitable organizations.

When participants chose to donate money, the brain's mesolimbic system was activated -- the same part of the brain that's activated in response to monetary rewards, sex and other positive stimuli. Choosing to donate also activated the brain's subgenual area, the part of the brain that produces feel-good chemicals, like oxytocin, that promote social bonding.

Why doing good works
These results may seem surprising, especially since our culture tends to associate happiness with getting something. Why should we humans be programmed to respond so positively to giving?

"As Darwin noted, group selection played a strong role in human evolution. If something like helping benefits the group, it will be associated with pleasure and happiness," explains Stephen Post, Ph.D., a research professor of bioethics at Case Western Reserve University, who co-authored the book "Why Good Things Happen to Good People" with Jill Neimark.

While evolution may have primed us to feel good from giving, it may not be the only reason that helping others makes us feel better. Since depression, anxiety and stress involve a high degree of focus on the self, focusing on the needs of others literally helps shift our thinking.

"When you're experiencing compassion, benevolence, and kindness, they push aside the negative emotions," says Post. "One of the best ways to overcome stress is to do something to help someone else."

Even better, feeling good and doing good can combine to create a positive feedback loop, where doing good helps us to feel good and feeling good also makes us more likely to do good.

How to help others -- and yourself
Incorporating kindness into your daily life isn't difficult. Here are five easy things you can do to help others -- and yourself:

Volunteer
Research shows that people who volunteer just two hours per week (about 100 hours per year) have better physical health and are less depressed. To find volunteer opportunities in your area, search the Internet or contact your local church or school.

Informally offer help to family, friends and neighbors
Lend a needed tool, bring dinner to someone who's sick, feed pets for neighbors on vacation or offer a ride to someone who lacks a car.

Donate
It doesn't have to be a lot of money. Toss change into coffee cans at cash registers or support local organizations by buying a raffle ticket. Look for opportunities to give within your means. You'll help make the world a better place and make yourself feel better too.

Listen
Sometimes all others need is someone to lend a sympathetic ear to make them feel heard, cared for and loved.

Make other people (and yourself) smile
The easiest way to make other people happy is to act happy yourself, even if it's not how you feel. "Sometimes we can act ourselves into a way of thinking," says David Myers, Ph.D., a social psychologist and author of "The Pursuit of Happiness." "So like the old song says, 'Put on a happy face.' Talk as if you have self-esteem and are outgoing and optimistic. Going through the motions can awaken the emotions."