Dogs were domesticated over 15,000 years ago and have been constant companions ever since. According to surveys, over 60 million American households include a dog. This makes dogs the most popular pet among Americans. Other pets don’t even come close. Nearly 28% more U.S. households have a dog than a cat.

Can this be explained rationally? Maybe the top entry on a list of the reasons why dogs are good pets should simply be “people love dogs.” Accepting that as true, here are five other reasons why dogs are good pets:

Physical Health

Dogs have profound positive effects on the health of their owners. Dog owners are more likely to exercise with their dogs, leading to many of the benefits of working out. Studies have shown that dog ownership is associated with:

  • Lower serum cholesterol
  • Lower blood pressure
  • Lower triglyceride levels
  • Higher survival rates of heart attacks

Paradoxically, dog owners are less likely to suffer allergies and infectious diseases. This has led scientists to theorize that dogs have a positive effect on the body’s immune system by exposing dog owners to allergens and microbes carried by dogs.

These health benefits are not a one-way street. Stray dogs have an average life span of about five years and have a very high puppy mortality rate. Pet dogs, due in large part to better nutrition and access to veterinary care, have a life expectancy of 10 to 15 years, depending on the breed.

Mental Health

Dogs also improve our happiness. This is not merely anecdotal. Looking into your dog’s eyes triggers the release of oxytocin, the same hormone responsible for bonding us to our babies and our romantic companions. Oxytocin works with neurotransmitters like dopamine and serotonin to strengthen the brain’s association between our dog and our own happiness. Why are dogs good pets? So far, dogs are the only non-humans found to trigger this biochemical response in humans.

The truly fascinating part of this interaction is that dogs also experience a release of oxytocin, creating a two-way bond analogous to the bond between a parent and child or the bond between romantic lovers. So, adding to the reasons why dogs are good pets, we can say that dogs love people just as much as people love dogs.

Social

Although it is difficult to explain causation, dog owners are more social than non-dog owners. Specifically, studies have shown that park-goers are more likely to talk to other park-goers if one of them has a dog. Whether the dog actually changes our social behavior or just provides an ice breaker to talking to strangers, improving our social lives is among the reasons why dogs are good pets.

Security

The original purpose for domesticating dogs, aside from eating our trash and killing vermin, was to warn us when predators, including other humans, approached our camps. Dogs still perform this service for their families to this day. Many joggers prefer to run with their dogs rather than other joggers because dogs intimidate would-be attackers from attacking.

However, security is not limited to big dogs. In fact, many of the 157 small dog breeds were bred to be watchdogs. Shih Tzu and Lhasa Apso, for example, may be small but were bred specifically to guard Tibetan Buddhist temples. These dogs do not yap at strangers, they warn intruders not to mess with their families.

Make Us Better People

While it may seem self-centered, one of the reasons why dogs are good pets is that dogs make us better people. Dog owners tend to have lower levels of the stress hormone cortisol when they are interacting with their dogs. Cortisol affects people differently but has been associated with anxiety, irritability, and depression, particularly in people with post-traumatic stress disorder (PTSD). Even in dog owners suffering from ordinary stress, interacting with their dogs improves their mood and makes them more productive.

Moreover, children raised with dogs tend to be more empathetic and compassionate. Dogs help children (and probably adults) regulate their emotions since they are often a mirror reflecting our own emotions, getting upset when we are upset and calming down when we are calm.

There are measurable reasons why dogs are good pets, from their effects on our health to helping us better understand ourselves.