Life's Great Mysteries - Why do dogs love to chase balls?

In April, Trish and I spent some time on the Pacific coast of Washington state. At one particular stop, I noticed a man playing with his dog on the beach, and I captured a fun photo.

Later, as I stared at the photo, I realized the man had a special throwing handle, which allowed him to throw a ball farther and throw it repeatedly without undue stress on his arm. The key word here is "repeatedly." Because we all know some dogs seem to never get tired of fetching a ball. So, I wondered, why do dogs love fetching balls (or other objects) so much? Let's dig into this.

First, there is the obvious: Dogs like to please people and interact with people, and playing a game like fetch accomplishes both. And, of course, dogs like to run.

But there's a much deeper motivation involved. As I've discussed in previous emails, all domestic dogs come from a common ancestor that was also an ancestor of the gray wolf. Like the wolves of today, this ancestor was a predator. So, domestic dogs evolved from a successful, efficient predator. A killing machine, if you will.

This ancestor had a strong prey drive (the instinctive drive for carnivores to pursue and capture prey). Today's domestic dogs still retain some of this prey drive, though humans have bred portions of this instinct out of some breeds more than others.

Biologists often break the predatory sequence into several steps: Search → Stalk → Chase → Bite (kill) → Dissect → Consume. Different parts of this sequence are still strong instincts in domestic dogs, particularly the first four (search, stalk, chase, and bite). Humans have bred dogs specifically to emphasize some of these steps. Some, like bloodhounds, were bred to amplify the search stage (using smell). Herding dogs have been bred to enhance search, stalk, and chase, but to reduce the bite (kill) step, to avoid danger to the livestock they are supposed to protect. And some dogs were bred to retain most of the entire sequence, such as rat terriers, bred to find and kill varmints.

Most dog breeds have, to some extent, retained the chase and bite portions of the sequence. And this, of course, is why dogs love to chase balls over and over. Dogs are irresistibly drawn to chasing things that move. And they like biting and chewing these things when they catch them. When a dog grabs a ball or other dog toy and shakes it, the dog is essentially "killing" it (like breaking the neck of a small critter). And, of course, dogs like to chew things up and tear them to pieces because this is the "dissect" portion of the sequence. Unfortunately, some dogs even get sick because they ingest portions their toys (the "consume" portion of the sequence).

This love of chasing balls is reinforced by the dogs' desire to interact with people. Which in itself is a result of thousands of years of the symbiotic relationship between humans and dogs.

Photo Credit:
- Man and dog on beach - Stan C. Smith