http://info.thinkfun.com/stem-education/mans-best-friend-the-science-behind-the-dog-and-human-relationship
Man’s Best Friend: The Science Behind the Dog and Human Relationship
It’s been a long day at work. You’re exhausted and ready to crash. You open the door, and suddenly there’s a wet nose, wagging tail, and slobbery kiss to greet you. It would seem that your arrival is the highlight of a dog’s day, and it very well might be. You greet your friend and look into his happy face, grateful for the companionship.
The bond between humans and dogs has lasted thousands of years and has even shaped the way our brains have developed. Our canine companions affect us in a surprising amount of ways, from boosting our immune systems to staving off dementia. With everything that dogs do for us, it’s no wonder they’ve been nicknamed “man’s best friend”.
Our history with dogs goes farther back than our history with domesticated livestock, including sheep and cows. Evidence has been found that supports dogs and humans living together as far back as 13,000 years. Initially, packs of wolves would follow humans, looking for food scraps. At some point the friendlier wolves approached the humans, who in turn took them in as companions. The bond was mutually beneficial in that humans could provide shelter and protection, and wolves could help bring down prey. Friendly wolves were bred with other friendly wolves, to eventually become dogs. What’s interesting about this, is that dogs evolved alongside humans, so they are able to connect with us on a deeper level than many animals today.
Research conducted by Emory University sought to find out if dogs preferred receiving treats or praise. Scientists began by training thirteen dogs to associate three different objects with different outcomes. A blue toy knight signaled verbal praise, a pink toy truck signaled a treat, and a hairbrush signaled no reward, and was a control. Each dog was tested 32 times using an fMRI machine to scan their neural activity. All of the dogs showed more neural activation for the reward stimuli over the control hairbrush. Four of the dogs showed a stronger activation for the praise over the treat stimulus, and nine showed similar neural activation for both the praise and the treat stimulus.“Dogs are hypersocial with humans,” says Emory neuroscientist Gregory Berns, “and their integration into human ecology makes dogs a unique model for studying cross-species social bonding.”
This isn’t the only evidence of human-dog bonding. Dogs are one of the few animals that understand abstract thinking, such as looking at an object a human is pointing to rather than looking at the finger itself.A recent studyconducted in Hungary suggested that dogs process language the same way that humans do, and that they are able to distinguish significant words from insignificant. Dogs are also able to recognize human faces both in photographs and in person, processing the images in the part of the brain that deals with communication, emotional expression, and storing memories. None of these traits are present in wolves, which suggests that human influence has gone a long way in the development of the dog.
While it is interesting to note the evolution from wolf to dog, the effect dogs have had on humanity could be considered just as fascinating. Recent research has found that looking into a dog’s eyes activates the same hormonal response that bonds us to human babies. Scientists at Azabu University in Japan brought in 30 dog owners and a few wolf owners for the experiment. Owners were asked to stare into the eyes of the animals for a set period of time, with urine samples collected from all participants before and after the study. The result was that the dogs who stared the longest into their owner’s eyes experienced a 130 percent rise in oxytocin levels (a chemical associated with the feeling of happiness), with the owners experiencing a 300 percent rise in oxytocin. None of the wolf-owner duos experienced an increase in oxytocin. This could explain why we feel so attached to our furry companions, even going to far as to treat them like children.
Today, as it was thousands of years ago, dogs are not just companions. Service dogs, therapy dogs, herding, and police dogs are everywhere in Western society, with new positions evolving constantly. More than 2,300 reading education assistance dogs around the country are helping children to improve their literacy skills by simply being present. Children who are uncomfortable reading aloud to people are able to practice with a nonjudgmental companion, and are more likely to practice words they do not immediately recognize. In one study, children who read to dogs over the course of 10 weeks exhibited a 12 percent improvement in reading skills, while those who did not read to a dog showed no improvement.
Dogs can have a huge impact on the development of children, both physically and mentally. A 2012 report in the journalPediatricsstates that children who grow up in home with a pet are less likely to get sick than children who live pet-free. Researchers believe that by exposing children to pet dander and other microbes brought in from outside, children’s immune systems get an early boost in development. This early exposure helps them fend off illness later on in life, and results in less use of antibiotics that could cause bacterial resistance.
Another study found that children who owned a dog were more empathetic and pro-social compared to children who grew up without a dog in the house. Children also reported higher levels of positivity about their home and family when they had a strong bond with the dog. Children can greatly benefit from the love given and received by four-legged family members who provide unconditional comfort.
The benefits boosted by our furry friends can be observed in both children and adults alike. Dog owners, on average, have lower blood pressure, lower cholesterol levels, fewer hearts attacks, and suffer from less medical problems on average. This could be in part because dog owners typically take their dogs on walks, which is part of a healthy lifestyle. Dogs also encourage humans to be more social.Studieshave found that 40% of people reported making friends much easier as the result of owning a dog. And you know that happy feeling you get at the end of a long work day when you see your furry friend? People who own dogs have the lowest response to stress. It really does seem like dogs make us better people!
The bond between dogs and humans is a truly special thing. Not everyone can own a dog, but that doesn’t mean that you can’t enjoy quality time with a canine companion. Shelters all around the country are always in need of volunteers to help with the dogs. Fostering a dog can be a rewarding and temporary opportunity to enjoy the benefits of the canine-human relationship. Working with dogs can develop social skills in children and can be therapeutic for adults. Dogs bring so much joy to people and it’s so easy to return the favor. They are man’s best friend, and as of yet, there’s no competition for the title. Just keep all of this in mind when Fido tears up your new sneakers!
你会发现，曾经以为很难做到的事情，
