When people walk their dogs, strangers often stop and say, "Your dog is so cute!" A study asked about 2,700 people in four cities about their pets and neighbors.

Pet owners were more likely to know people in their neighborhood. About 40 percent of them got help from people they met through their pets. But scientists have not proved that pets make everyone happier or healthier.

Dog owners often find that strangers start conversations with them during walks. A 2015 study examined this effect through a phone survey of about 2,700 randomly selected residents of Perth in Australia and three American cities. Pet owners were more likely than non-owners to have got to know people in their neighborhood.

In the American cities, dog owners were especially likely to consider people they met through their pets to be friends, and about 40 percent of pet owners had received some kind of support from such people. In another study, couples did stressful tasks, and pet owners showed smaller increases in heart rate and blood pressure when their pet was present. However, a review concluded that the overall evidence that pets improve health and happiness is mixed.

Walk a dog and strangers will often stop to chat. Researchers have asked whether pets work as a catalyst for human relationships. In a 2015 telephone survey of about 2,700 randomly selected residents of Perth, Australia, and three US cities, pet owners were more likely than non-owners to know people in their neighborhood. Dog owners in the US cities were more likely than other pet owners to count such acquaintances as friends.

Roughly 40 percent of pet owners had received social support, such as advice or practical help, from people met through their pets. Because the survey was cross-sectional, it cannot show that the pets caused any of this. A review has also pointed out that some studies found pet owners to be less healthy or happy.

So the "pet effect" is a hypothesis for now. Pets may offer support directly as well. In one experiment, people who had just recalled being rejected felt better after writing about their pet, as much as after writing about a best friend. Among 240 married couples doing stressful tasks, owners showed the smallest physiological stress responses when their pet was in the room, perhaps because animals do not judge.