Evolution, food rewards, dog training, and human behavior

Every beginning biology course in high school or college starts out pretty much the same way, with the same question: “how do you know if something is alive?” The students are then guided to the answers: whatever it is takes in nutrients, excretes waste material, and reproduces itself. Food and sex! The essentials of life. (And shit? Well, shit happens.)

Evolution is an amazing thing. Over the four and a half billion years of our planet’s history, life on earth has evolved from the very simplest single-celled organisms to that vast complexity of mammals (and birds, and octopuses, and honeybees, and so on). Let me stress the fundamental identity of life: food and sex. The earliest evidence for life on earth is found in rocks that are three-and-a-half billion years old. (To give an analogy here: if you spread your arms wide, and that distance represents the time span of life on earth, you can erase all of human history simply by filing down the nail on your middle finger. Three and a half billion years is a very long time.)

During all those billions of years, the organisms on earth depended on two things to ensure their longterm survival: food and sex. They had to take in enough nourishment to survive, and then enough excess nourishment to go beyond survival and all the way to reproduction. As a result of evolution, where only those organisms that were good at taking in enough extra nourishment made it to the reproduction part, there are huge mechanisms built into life forms to ensure that the drive for food is first and foremost in the actions that all life takes. (You could argue that there are times when sex is more important–the spawning of salmon would be an example–but those times always come after the organism is well fed.)

Why do I bring this up? Because it begins to explain why training your dog with food is the easiest way to train your dog. Because taking in nourishment is so evolutionarily advantageous that eating is hugely rewarding. Because eating is important in the life of any living creature.

There are a few things that dog trainers tell each other over and over, and one of them is “what gets rewarded gets repeated.” Two corollaries to that are that reward rate (timing) matters and reward quality matters.

In one of her books Karen Pryor writes about training a hermit crab to ring a bell by using a marker and a food reward. Now, hermit crabs are not nearly as smart as dogs (or humans) and yet a consistent food reward works to train at least one hermit crab. The drive for food is amazing.

To train dogs in agility (or any of the dog sports), we have to work at associating the behaviors we want with the primary and secondary rewards we offer. We can develop secondary rewards (throwing a ball, saying “good boy!”) by associating them with the primary reward of food. If you always say “good dog!” and then give the dog his food reward, the dog learns that “good dog!” means a reward is coming, and the words become a reward of their own–as long as you pair those words with food most of the time. This is the principle that is used in clicker training: the click predicts a food reward; marking the behavior with the click tells the dog (or other animal with a brainstem) that behavior predicts a food reward; the dog tries repeating the behavior that earned the click/food reward; the dog again receives the click/reward; the behavior is gradually trained.

For our dogs, who are usually pretty well-nourished (as dog trainers, we want our dogs to be in optimum health), some other activities can become primary rewards. Playing with toys or chasing balls is very rewarding for many dogs. For some herding breed dogs, the opportunity to herd is rewarding. The dog defines the reward, not the trainer!

Reward rate and timing matter a lot, because in training you’re trying to persuade a deep part of the animal’s brain stem that “this behavior, this one right now, predicts food acquisition.”* A high reward rate allows you many opportunities to form that connection; timing helps pinpoint the behavior. Sometimes when I’m training Rush or Dancer I pick a simple behavior–one I’ve trained before–and work on reinforcing my training by trying to reward that behavior with really good timing and really good rewards. Recalls are great for this, because we all need a really good recall.

As far as human training goes, I’ve written a lot about dog training in this blog over the years. I think this is the first time I’ve written about evolution, though. It’s because I’ve been thinking a lot about food for the last few months; I’m going through a challenging** time with my efforts to lose weight. The fact is that we (American) humans are going through a time of unprecedented food availability and we still have three-and-a-half billion years of evolution telling us to eat, eat now, eat now!, and only a few hundred thousand years of human self-awareness and intelligence saying “um, maybe not so much.”

The evolutionary drive to take in nourishment–to seek out food and eat it–is enormous. Think of it in the same light as trying to keep a teenage boy from thinking about sex, and the problem of reasonable food intake (instead of overeating) becomes far more understandable. I spend a lot of time thinking about how to create reward systems for myself that reward not eating. Or that reward behaviors that lead to my goal of weighing less and being more fit. I recently bought myself a pair of pink and gray Hoka One One Clifton 2 running shoes as a reward for all the training (and not-eating) I did that led to a new personal record (for my current age) in a 5K run. I love the Clifton 2s; the generous padding has meant that I don’t have knee or foot problems even as I increase my running distances.

*Think about plants. Even in plants, the reward of “food” also functions to change behavior. Plants grow toward light, which they use as energy source in photosynthesis. Light is not the same thing as food, I acknowledge, but since the point of food acquisition in organisms is to have energy for life, I will argue that the primal need is much the same.

**I have taught myself to use the word “challenging” instead of “hard” or “difficult” or “impossible” for all kinds of situations, from ignoring chocolate cake to agility handling to running a 5K. Challenges are good, I like challenges, and it’s possible (most of the time) to meet challenges and overcome them. There are methods for dealing with challenges. Just saying something is “hard” doesn’t help you get past it. At least, that’s how my brain works.