After reviewing Different. Gender issues seen through the eyes of a primatologist, we wanted to have a chat with the author, the primatologist Frans de Waal, to find out what motivated him to deal with gender issues and to get his opinion on research in this and other fields of ethology. Here is our interview.

In your studies (and in your books), you have tackled various themes, investigating in other animals aspects ranging from emotions to intelligence. How did you come to the topic of gender, and what motivated you to address it?

It seems to me that there is a lot of skepticism in issues concerning gender. Very often, in the media, it is said that gender is a cultural issue, something invented that we can easily change. And I noticed that, whenever I give a lecture and talk about sex-related differences in behavior, people want to know more. I believe this is because, in general, they can't get answers from psychologists or other human behavior scientists, because many of them are now reluctant – and perhaps skeptical - to talk about sex differences, they get into trouble if they say “men do more of this and women do more of that”. As a primatologist, on the other hand, I can talk about it in a way that's easier to accept, simply describing what we see in primates.

That's why I wanted to write a book on these topics. Initially, I wanted to talk only about males and females and how they differ in primates, in humans, and so on. But, to my own surprise, I found myself also addressing the theme of gender diversity, because while writing I noticed that I know many individuals who behave differently from the typical male and female models. Just like in humans, we have typical males and females, but also a huge individual variability in gender-related behaviors. So I started to explore a bit of this aspect as well.

You make it clear, throughout the discussion, that what we can observe in our closest relatives is not a justification for our behaviors or for controversial and discriminatory choices. What then is the value of studying aspects related to sex and gender in other species? In other words, why do you think it is important to try to understand the biological aspects, distinguishing them from the cultural ones?

Of course, there is always a biological component in human behavior; there is no purely cultural behavior. And there isn't because, after all, what is culture? Not an external force, like the weather: culture is ourselves. We influence each other and call this influence culture. Other primates have a culture too: they learn many things throughout their lives, all the more so as chimpanzees and bonobos become adults around the age of 16, so they have a huge amount of things to learn and time to do it. Culture, in short, always interacts with “nature”, as they say. Humans essentially come in two forms: female and male, and some intermediate forms, and our behavior is shaped by the environment but also by our biology. Environment and biology cannot be easily separated: you think you can do it, to say "this is purely biological and this is purely cultural", but pure forms don't exist; it's always, always an interaction between biology and environment. The same applies to other species.

So we find ourselves making a complex comparison, where we see that some aspects are universal and found in all humans around the world and in all primates. And, if they are universal, then biology is probably involved in some way. Then there are differences that appear between one country and another in humans, or from one species to another in primates. So they are not universal and, in this case, we can say that these are more flexible aspects. I still think it's important to look at biology: we can't escape it.

At the same time, biology is often portrayed in a simplistic way - and I must say that we biologists have been partly responsible for this view. For example, in the 70s and 80s, we had books like those of Richard Dawkins, who said that we are slaves to our genes, that we are here to execute their programs. It's a very deterministic and reductionist way of looking at human or animal behavior: we are not slaves to our genes. We biologists have also simplified the narrative about animals and humans by making statements like: "we have a typical male behavior and a typical female behavior", while there is, instead, a huge variability. If you look in a forest, you immediately see that even two trees of the same species are different from each other. Individual variability is ubiquitous and drives evolution, which could not occur if individuals were not different in their genetic makeup.

Unfortunately, the excessive simplification we have made has led biology to become the enemy in the gender debate, because it is often perceived as rigid and inflexible and as if the path between genetics and human behavior were one-way. But no: it's a two-way street. I think that when people are suspicious or disappointed regarding biology in the gender debate, it's because we did not do a good job in explaining how flexible biology can be in people, and how flexible it is also in other primates. In my book, I described individual primates who are a bit different from the others: some have more homosexual than heterosexual behavior; some do not behave according to the typical gender model of the species. Here too, there's a lot of individual variability, and I tried to explain that the same variability we see in human society we also see in the societies of other primates.

The only big difference I see between us and other primates is that we are more intolerant of these differences. I have never noticed that other primates have problems or reject different individuals, but human society is very tied to norms and rules, tends to make classifications and place labels on all behaviors. I believe this is the biggest difference.

Globally, where do you think research on the theme of sex and gender in other animals is at? And how much interest does it gather among scientists?

We primatologists (and I think this is also true for many others who study animal behavior) still have a lot of work to do on this theme: so far, we have looked for the most typical models. We do the same in human society, where we talk about "typical men" and "typical women" and much less about those who are atypical. But I would say that, in a group of primates, one in ten, or maybe one in twenty, does not behave exactly as one would expect in terms of role or gender behavior. I think the same is true for human society. We need to accept that variability exists and is very common. Recently I've seen some articles, one of which was about the homosexual behavior of chimpanzees in nature; for bonobos, it has been known for a very, very long time - I usually describe them as bisexual, because I don't think they make a big distinction between having sex with a male or with a female, so for them the term homosexual isn't even applicable. But in other animals we've somewhat neglected the topic and focused on the most common behavior, which we've considered to be heterosexual, while there is also a lot of variability there. We need to focus more on these gender-related models and on all the variability that exists, and also on personality - as we do in humans.

You have worked on so many different aspects of animal ethology: can we ask you what you are working on, or intend to work on, now? In which direction do you think to steer your work?

I am now retired and not doing much research: by now, most of my activity is in giving lectures and writing books. However, I am still a bit involved in empathy, a topic that interests me a lot. I am interested in the differences in empathy between chimpanzees and bonobos, between males and females, between young and old. The research on empathy has now extended to many other species: dogs, dolphins, elephants... There are also many studies on rodents, such as mice and rats, which often also consider the neuroscientific aspects of empathy. This is a field that is becoming very important. For about 25 years, studies have focused on cognition and animal intelligence and several articles come out on these topics every week.

But I believe that emotions, consciousness, and awareness, so the inner life of animals, and especially the way they express emotions and how important they are to them, is becoming an emerging topic. All the more so as many studies about it increasingly involve neuroscience. As for primates, neuroscience studies are more difficult, especially if we want to avoid, as I think is right, invasive studies. We indeed need to start conducting neuroscience studies on other primates in the same way we do for our species, where a person is placed in a scanner and we observe how the brain responds to questions or situations that are presented. I believe this will happen in the future for all species: after all, it's already happening for example with dogs. There are indeed some studies in which dogs are trained to stay still in a scanner and we observe what happens in the brain. This is the direction I think we need to go.