They’ve been our companions for tens of thousands of years. They share our beds, follow us into the bathroom, and star in our holiday cards. The beautiful friendship between Homo sapiens and Canis lupus familiaris has had some surprising effects on both species—read on to learn more about the ways we’ve helped each other along the way.

1. IMPROVED IMMUNITY

Living with furry friends, especially dogs, has been shown to decrease babies’ and kids’ risk for asthma, allergies, and other immune conditions. Some studies have found that the benefits can begin as early as the womb. Scientists aren’t completely sure why this happens; it may be that bacteria on the dogs’ bodies can help give our immune systems a boost during a crucial moment in our development.

2. INCREASED FOCUS

Keeping your phone loaded with pictures of your pet may pay off in the long run. In one 2012 experiment, people who looked at pictures of puppies scored higher on tasks that required their close attention. Photos of older dogs were less effective; the researchers say it might be that baby animals inspire a specific type of positive emotion and mental activation.

3. A THIRST FOR PRAISE

Dogs are social animals; that’s part of the reason we were able to tame them in the first place. And once we take them in, they really start to care what we think. Experiments with dogs and their owners have shown that when given the choice between snacks and praise, most prefer being told what good dogs they are.

4. MORE CHILL

Sharing your life with a drooling, adoring furry friend is good for your attitude and your stress levels. Spending time with dogs can ease tension and stress. Studies have found that this is especially true in high-stress situations like crises, natural disasters, and the office.

5. HEALTHIER HEARTS

Reduced stress is its own reward, but it can also have long-term health benefits, including lower blood pressure, lowered heart rate, and a decreased risk of heart disease. This works even in little doses: just petting a dog for a few minutes sends feel-good chemicals to the brain and can soothe a frazzled nervous system.

6. INTERSPECIES EMPATHY

All those millennia together have made a real impression on dogs’ brains. One 2016 study found that dogs could read and respond to the emotions on human faces, even in photographs. This is especially cool when you consider the major differences in body language between our two species. Dogs don’t smile, but they still know what our grin means when they see it.

7. MORE EXERCISE

There’s nothing like an “I’ve-got-to-pee-RIGHT-NOW” bark to get you up and out the door. For obvious reasons, dog owners get more casual exercise than other people. This, in turn, can also lower stress levels and improve heart health.

8. LANGUAGE LEARNING

Spoken language, like body language, differs drastically between our two species, but that hasn’t stopped dogs from trying to figure ours out. A series of Hungarian experiments using MRI scanners found that dogs’ brains responded to human voices speaking both positive words and with positive tone. This was true even when the positive words were spoken in a neutral tone (“good boy”) and the positive tone was applied to a neutral phrase (“however!!!”). They get us.

9. A SOFT, COMFY LIFE

The good news for dogs is that domestication has given them a steady source of food, shelter, and companionship. The bad news is that all this cushy living has dulled their edges somewhat. Compared to the wolves from which they descended, pet dogs have weaker senses of hearing and smell, and they’re worse at problem-solving tasks. But this isn’t a problem, per se; they’ve simply evolved and been bred to prioritize one set of survival skills (coexisting with people) over another (sharp senses and keen minds).

10. GENETIC CONNECTION

The bond between us and our dogs is real, and may trace all the way down into dogs’ DNA. Experiments have found that the most sociable pet dogs have genetic mutations that appear to make them more interested in people. Without these abnormalities, experts say, we might never have been able to domesticate dogs in the first place.

Dogs make our lives a whole lot happier and healthier. (You can’t argue with science!) Looking to return the favor? Consider a monthly subscription to BarkBox. Your favorite pup will get a package filled with treats, toys, and other goodies. Visit BarkBox to learn more.