A new relationship with animals, nature and each other.

Who Stops for a Turtle in the Road?

. . .and what this says about the new science of human-animal relationships

By Hal Herzog

Three years ago, a group of Canadian biologists decided to find out how different people react when they’re driving a car and they see a helpless animal on the road in front of them.

The study is all part of the new science of human-animal interactions, known as anthrozoology, which springs, in part, from the ideas of French anthropologist Claude Levi-Strauss, who said we could learn a lot about human nature by studying how we think about and act toward other species.
“Animals,” he wrote, “are good to think with.”

Who drove on, who ran them over and who stopped to help?

The experiment by the Canadian biologists was simple and elegant in its design. The scientists would place realistic rubber models of a turtle and a non-poisonous snake in the middle of a two-lane rural highway and watched what happened.

They would also include a turtle-size Styrofoam cup and a thick line of grease the size of the snake to act as controls in the study.

We can learn a lot about human nature by studying how we think about and act toward other species.

During the trials, either one of the animal models or one of the control stimuli (the cup or the line of grease) was put on the center line of the road. The researchers recorded whether the drivers ignored the object, swerved to intentionally hit it, or pulled over to the side of road and rescued the model. (No one tried to rescue the plastic cup or the streak of grease.) They ran 500 trials for each of the four stimuli, and they also noted the gender of the drivers.

The results: Most people were in the middle

What did the scientists learn about human-animal relationships by studying the number of intentional collisions between cars and fake reptiles?

The experiment showed that treatment of animals followed a bell-shaped curve: most people were in the middle, with fewer at either extreme.

A large majority of drivers (94 percent) just ignored the faux turtles and snakes and drove on by. Some, however, were extraordinarily kind, while a few others went out of their way to kill the fake reptiles. About 3 percent of drivers stopped, got out of their car and rescued the animal models. And another 3 percent of drivers swerved and intentionally ran over the “animals.”

Snakes fared worse than turtles

The scientists also noted that the “snakes” got run over more than the “turtles.” While the rate of turtle-squashing was only slightly higher than Styrofoam cup-squashing, three times as many fake snakes were “killed” as the same size and shape control stimulus.

Men were eight times more likely to run over the model snake than were women.

Fear of snakes is the most common animal phobia, even though you are one hundred times more likely to be maimed or killed by your neighbor’s dog than by a venomous serpent.

As I discuss in my new book, Some We Love, Some We Hate, Some We Eat: Why It’s So Hard To Think Straight Abut Animals, psychologists disagree about whether fear of snakes results from instinct, learning, or a general aversion to weird creatures. But, whatever the source of our animosity to snakes, some drivers want to kill them.

Men are not as nice as women

Several years ago, I reviewed the scientific literature on gender differences in human-animal interactions. I came to two conclusions:

The first was that in some areas, like attachment to pets, gender differences are small, while in others, like membership in animal protection organizations, they are large.

The second is that, with the exception of extreme hoarding, men are more likely to abuse animals than women. This gender difference clearly played out in the intentional road kill study. While only 2 percent of female drivers went out of their way to crush an animal, 7 percent of men did. This gender difference was particularly large in the fake snake trials, in which men were eight times more likely to run over the model snake than were women.

The new science of human-animal relationships

The intentional collision experiment shows how anthrozoology can shed unexpected light on many aspects of human behavior.

University of Pennsylvania psychologist Paul Rozin has noted out that when looking for general principles of human behavior, psychologists have tended to focus on broad topics such as learning, memory and motivation to the exclusion of things like leisure, preferences for food and music, and religion. Our relationships with animals also fall into the category of things that everyday people care about but most psychologists don’t. I do not know of a single undergraduate psychology textbook that includes a serious discussion of the effects of pets on human well being or on child development.

This situation, however, is changing. The National Institute of Child Health and Human Development, for example, recently joined with Mars, the corporate giant that makes Snickers for me and Tempting Tuna Treats for my cat Tilly, to fund a multimillion dollar research initiative on the impact of pets on children.

The study of our attitudes and behaviors toward animals is important for lots of reasons, but what I particularly like about the new science of human-animal relationships is that our interactions with other species pervade nearly every aspect of our lives – even the split-second decision to ignore, rescue, or obliterate a helpless turtle.


Hal Herzog is the author of Some We Love, Some We Hate, Some We Eat: Why It’s So Hard To Think Straight Abut Animals (Harper). He teaches biological psychology and studies human-animal interactions at Western Carolina University.