 Hello. Let's find out whether you, the audience, are smarter than the fish that I work with. I'm going to give you a task. You won't have much time to solve it, so try to do it as fast as you can. Ready? Count how many fish you see on this slide. Go! Okay, stop. You're out of time already. Now, the answer was 15, but if you didn't get it in that time, I'm afraid you are no smarter than a fish. They can do it in a split second. Now, brain is no doubt the most fascinating organ that ever evolved on this planet, yet we know so little about it. How can a fish, a size of a pinky finger, outsmart us? It's a mystery, and I want to know the answer. I want to know why some animals are smarter than others. So here's what I do. I design IQ tests for fish. I build special mazes and arenas so that I can measure their memory, learning, navigation skills, even their abilities to control emotions. After watching thousands and thousands of fish swim around the tank, I can give each fish a score and then I look for patterns. Are there differences between males and females, young and old? Does inbreeding or pollution affect intelligence? I compare fish performance to other animals, and I try to find biological explanations for the results that I see. There is one pattern in particular that I'd like to share with you today. Intelligence is an adaptation to problem solving. When animals face certain challenges in their lives, we expect that over time they might evolve intelligence to deal with these problems. Okay, sure. But what happens, say, if males and females, for some reason, face different challenges? Well, in that case, we expect that males and females will evolve different intelligence independently. For example, our male fish right here happen to be quite aggressive. They do a lot of fighting. And I found that their ability to control emotions is actually quite poor compared to that of the females who provide parental care and avoid impulsive actions. But sometimes we find no differences between the sexes at all. Let's suppose there is a predator nearby. As a fish, you want to quickly find the largest group of other fish and swim away to safety. You see a bunch of your fish friends over here, some fish buddies over there. Which group do you join? Well, you've got to count them first to find the largest group. This is why fish are so good at counting because for them it is the matter of life and death. But we humans face different challenges in our lives, like attempting to communicate effectively in under three minutes. Intelligence is an adaptation to problem solving. Being smart doesn't mean that you can count very fast. It means you're well adapted to your environment. So as you can see, my little fish friends might not look very impressive, but they helped me answer some of the most interesting questions in the field of animal intelligence. Thank you.