Animal Attraction: Beauty Is in the Brain of the Beholder

An interview with Michael Ryan about "A Taste for the Beautiful"

Posted Feb 02, 2018

There are no free lunches in the sexual marketplace. Regardless of how traits and preferences evolve, they incur costs as well as reap benefits. ... A hallmark of sexually attractive traits is that they are costly. (A Taste for the Beautiful, p. 155)

Michael Ryan
Source: Michael Ryan

When I first learned of award-winning University of Texas zoologist Dr. Michael Ryan's new book called A Taste for the Beautiful: The Evolution of AttractionI eagerly looked forward to reading it. As I did, I wasn't let down at all. In fact, something on every single page grabbed my attention because while I know a good deal about evolutionary theory, my knowledge of sexual selection and the evolution of beauty is pretty basic. When I got done reading A Taste for the Beautiful, my brain was full of new facts and ideas about animal attraction and the whys and the hows of sexual selection. And, of course, the brilliant work of Charles Darwin comes to the fore in many places. To wit, part of the description for Ryan's book reads:

Darwin developed the theory of sexual selection to explain why the animal world abounds in stunning beauty, from the brilliant colors of butterflies and fishes to the songs of birds and frogs. He argued that animals have “a taste for the beautiful” that drives their potential mates to evolve features that make them more sexually attractive and reproductively successful. But if Darwin explained why sexual beauty evolved in animals, he struggled to understand how.

I wanted to know more about Dr. Ryan's book, so I reached out hoping he could take the time to answer a few questions. I'm thrilled he was able to and our brief interview follows.

Why did you write A Taste for the Beautiful?

For years — in fact for decades — I have been studying sexual beauty. Although most of my studies are with frogs and some with fishes, I have always been broadly interested in this topic. I think there is a new perspective on the subject that has been emerging over the past years; that is, the importance of biases in an animal’s sensory, perceptual, and cognitive systems in influencing perceptions of beauty.

This book is written for the general public. I have found over the years that not only the undergraduates I teach, but also family and friends with little or no science background, find this topic fascinating. I wrote this book so I could share these stories.

How did you get interested in this fascinating topic?

Like many other animals, male frogs have sexual signals that encode their species identity, and females choose males of the correct species. In frogs the sexual signals are mating calls. While studying territoriality in bullfrogs I realized that I could tell the difference between males by their voice and I wondered if females could do the same, and if variation in the calls of males made them more or less attractive to females. This was right about the time sexual selection was becoming popular and there were no experimental studies to show that variation in sexual displays influenced female mate choice. I never did those studies with bullfrogs, but I decided to work in the tropics where the breeding seasons are longer and I would be able to gather more data. So I went to Panama to work at the Smithsonian Tropical Research Institute and a staff scientist there, Stan Rand, introduced me to túngara frogs. That was in 1978. Stan and I worked together until he passed away in 2005.

What are your main messages?

Beauty can be in the eye of the beholder, but more broadly beauty is in the brain of the beholder, and to understand the evolution of beauty we need to understand the sexual brain of those who assess beauty.

The brain might be our most important sex organ, but the brain has other things on its mind. The other tasks that the brain evolved to do, such as finding food and avoiding predators, can influence an organism’s perceptions of beauty.

Preferences for sexual beauty can be fickle and can change with time, within a day, within a breeding season, and as animal's age, and preferences are notoriously subjected to peer pressure.

Why should people care about the evolution of attraction and what are some of the practical applications of what we know about this topic? I'm thinking here about how our knowledge can be used to help various nonhuman species and also how humans might use this information for themselves.

We are all interested in biodiversity, but biodiversity is more than just the number of species. The diversity of organisms that excites many of us, scientists and nonscientists alike, is the incredible beauty that surrounds us in nature. Understanding where that beauty comes from, I hope, will give all of us a better appreciation of this particular flavor of biodiversity.

In our own species, knowing how the brain influences perceptions of beauty and all of the other nuances that bias our perception of beauty should lead us to a better appreciation of the physical diversity we encounter every day in our own species.

Who is your intended audience?

I am hoping that this book will appeal to biologists and psychologists, even though the main audience is the general public.

What are some of your current and future projects?

My colleagues and I are still working on sexual communication in frogs. We are very interested in how what economists call ‘irrationality’ influences decision-making during mate choice by frogs. We are finding that frogs share a lot of these irrationalities with humans.

Somewhat related, we are interested in cognitive overload; specifically, how much information is too much and can too much information actually lead to maladaptive decisions.

Beauty is all around us, and it is intoxicatingly diverse. (A Taste for the Beautiful, p. 169)

Permission of the publisher
Source: Permission of the publisher

Thank you very much, Mike, for taking the time to answer these questions. I hope A Taste for the Beautiful will enjoy a broad audience. I found it to be rather an easy read including material on topics with which I wasn't all that familiar. Although the book is packed with discussions of lots of scientific research and various theories, Dr. Ryan's prose is very clear and the book is well organized, so the material will be accessible to non-academics as well as to researchers and those more accustomed to reading scientific/research essays. Toward the end of the book, Dr. Ryan's discussion of Barbie, the iconic toy doll and her relationship to real parallels (pp. 160-161), ties together a good deal of information from earlier parts of the book. 

All in all, anyone who's interested in learning more about basic principles of attraction both in nonhumans and humans will walk away with a lot of new ideas about why nonhumans and humans have a taste for the beautiful. I'm sure many people will learn a good deal about their own preferences, hidden and otherwise.