Previous: Reinventing the Wheel: 5 Species That Roll
Next: How Anglerfishes Become One With Their Partners



View count:1,939
Last sync:
At the turn of the 20th century, scientists thought that insects were nothing more than tiny reflex machines. But Charles Henry Turner, who was possibly America’s first Black entomologist, ran some groundbreaking animal behavior studies that suggested otherwise.

Hosted by: Hank Green

SciShow has a spinoff podcast! It's called SciShow Tangents. Check it out at
Support SciShow by becoming a patron on Patreon:
Huge thanks go to the following Patreon supporters for helping us keep SciShow free for everyone forever:

Bd_Tmprd, Harrison Mills, Jeffrey Mckishen, James Knight, Christoph Schwanke, Jacob, Matt Curls, Sam Buck, Christopher R Boucher, Eric Jensen, Lehel Kovacs, Adam Brainard, Greg, Ash, Sam Lutfi, Piya Shedden, Scott Satovsky Jr, Charles Southerland, charles george, Alex Hackman, Chris Peters, Kevin Bealer
Looking for SciShow elsewhere on the internet?

Image Sources:
[♪ INTRO].

Scientists used to think bugs were just reflexive machines incapable of true decision-making or learning. Now, of course, we know that’s not true.

Insects are complex, cognitive creatures. And Charles Henry Turner—a researcher and school teacher who was possibly. America’s first Black entomologist—played a big role in helping the scientific community realize that.

His work laid the foundation for what we know about insect behavior— knowledge which has improved our understanding of everything from ecology to neuroscience. Nowadays, it’s common to see scientists researching the minds of bugs. Like, studying learning in bees to figure out how to increase crop pollination, or stimulating fly brains to understand how neural activity determines decision-making.

But, back at the dawn of the 20th century, biologists and psychologists alike believed that insects simply were not capable of that kind of thinking. They believed that all insect behavior could be explained by specific responses to specific stimuli. Like, one American physiologist wrote that caterpillars were “machines enslaved to the light.” But Charles Henry Turner thought there was much more to them than that, and he ended up being right.

Turner was born in Ohio in 1867, 2 years after the American Civil War ended. And from an early age, he took an interest in insects and other animals. He reportedly read book after book after book about bugs.

But books never seemed to sate his curiosity, so he began to study the natural world around him, too. After graduating first in his high school class, he went on to earn his Bachelor’s & Masters degrees from the University of Cincinnati, determined to have a scientific career. And his research was already starting to make waves.

Like, in 1892—the same year he earned his master’s— he published a summary of his thesis in the prestigious academic journal Science, which may have been the first Science paper from a Black scientist. And Turner was just getting started. By the time he got his Ph.

D. in 1907, he’d published roughly two dozen papers. Still, after obtaining his doctorate, he couldn’t get a professorship at a well-respected research university—probably because he was Black. So, in 1908, he accepted a teaching position at Sumner High School in St.

Louis with a starting salary of 1 thousand 80 dollars ($1,080) a year. That meant his equipment and resources were limited, and there’d be no undergraduate or graduate students to help him conduct research. But nothing could quell his insatiable curiosity.

His research ended up showing that insects and other animals can perceive their worlds much like we do, and the way they behave in response is surprisingly thoughtful. For instance, in 1910 and 1911, he published conclusive evidence that honeybees see colors and patterns, and that they use that information to make foraging decisions. That might seem like a pretty obvious conclusion now, since we are aware of how flowers can shape pollination activity.

But at the time, scientists questioned if bees could even see in color, let alone recognize patterns. What’s more: Turner’s clever experiments demonstrated that these insects can learn, too. See, in his experiments, he placed food for the bees in uniquely colored and patterned containers.

Once the animals discovered which container had the treat, they would seek out any container with the same color or pattern. Then he changed which containers contained the food. And it didn’t take long for the bees to switch to a new go-to vessel, showing that they learned from experience.

And Turner also realized bees weren’t special in their ability to learn. In one experiment, he trained cockroaches to behave totally unlike cockroaches and avoid darkness. He also conducted what many think were the first.

Pavlovian conditioning experiments in insects. That’s where one stimulus is paired with another to create a new, learned response to the original stimulus—a technique, of course, made famous by Russian physiologist Ivan Pavlov. Turner was trying to see if moths could hear airborne sounds— which, like with honeybee color vision, was debated at the time.

So, he contained moths in such a way that he could see their wings move, but they couldn’t fly away. Then, he played different sounds at them and recorded what happened. Most of the moths reacted very obviously to the various whistles and pipes he played, demonstrating that they could, indeed, hear.

The trouble was, one species didn’t. And he wasn’t sure if that was because the moths couldn’t hear, or if they just didn’t care about the sounds. So, he took those nonchalant moths and he played a particular sound while handling them roughly.

Lo and behold, after several bouts of this, the moths started to try and flee whenever he played that tone all by itself. So they could hear it— they’d just had no reason to react until it meant they were going to get roughed up. And they learned to have a different response to the sound over time.

That is textbook Pavlovian conditioning. Those are just some of Turner’s contributions to our understanding of animal behavior. He kept conducting his research until his death in 1923.

He published 41 papers in his 15 years at Sumner High, all while teaching high schoolers chemistry, biology, and psychology. That’s more than two papers per year, on average—which, for context, is higher than most of his contemporaries at colleges and universities. And Turner’s clever experimental protocols continue to receive praise today, especially since his experiments were some of the first animal behavior studies to employ solid controls.

His foundational research went on to be cited by the zoologists, entomologists, and psychologists that essentially established the field of comparative psychology. And now, that field is helping us figure out how neurons really work and how cognition happens in animals of all kinds, from the humblest of bugs to human beings. So, it’s fair to say that Charles Henry Turner helped start a revolution in how we think about thinking.

And all because he took the time to really observe the world around him, including species that many others had overlooked. If you enjoyed learning about Turner and how his work helped shape an entire field of science, you’ll probably enjoy our other episodes on pioneering scientists. Maybe you’d like to watch the one about Ada Lovelace next, and how she invented computer algorithms a century before computers even existed.

It and all of our episodes are available right here on YouTube for free! Because that’s what we do here: we make educational science videos for everybody. And if you really like what you see and want to help us continue to do that thing, you might consider joining our community of supporters at

Thanks for watching! [♪ OUTRO].