Would you be jealous if your partner had a sex robot?

Using sex-tech scenarios to understand the evolutionary basis of sexual jealousy

A theme of this Substack is how the technologies of the present and likely near future tap into our evolved appetites and preferences for friendship, intimacy, love, and sex. It’s a question I explored in my 2021 book, Artificial Intimacy. That book opens with sex robots, because they were very much the flavour of the several months I spent researching and writing the book. But I concluded they would be niche, and would soon be dwarfed in importance by matchmaker algorithms and what I called “virtual friends”. The explosion of conversational tech, from boy/girlfriend apps to ChatGPT, has vindicated and indeed exceeded that prediction. As a result, you will see a lot of Natural History of the Future concerns conversational technologies and their encroachment on friendship and intimacy.

One of the things I study, in my work as an evolutionary biologist, is human responses to the technologies of artificial intimacy. We sometimes do this using chatbots as experimental tools to study how humans grow close and fall in love. Or we set up scenarios, based on imaginary technologies and ask people to consider how they would react to those technologies. Today’s post is about a study – not from my lab – where researchers used the second approach to test somewhat controversial theories about the evolution of human-human sexual jealousy.

My former student Ash Prochzka and I have subsequenly done a somewhat similar study but on a wider range of sex-tech scenarios. I will write about that in a future post if this one proves popular or I receive even the most subtle form of encouragement. Or maybe I will do it anyway.

The article originally appeared on Medium, but I am occasionally introducing my Substack readers to these articles. I have edited it lightly, mostly to remove gross anachronisms.

Credit: Charles Deluvio on Unsplash

Sex robots, according to breathless media reports, are coming. Or, if not, then they are certainly on their way. Robotic androids and gynoids, animated by the 21st Century sorcery of artificial intelligence, stand ready to slide between the sheets and make themselves a part of our lives.

Reality, as it so often does, proves far more mundane. The current state of the art involves sex dolls that move in a few simple ways, and that talk like a simple chatbot. I call them dollbots because, from what I can discern, they haven’t quite arrived at sexbot central yet. Every year, however, sees quantum improvement in each of their constituent technologies, from robotic movement and skin warmth to better speech recognition and generation. And — despite all their limitations — since the COVID-19 lockdowns sex robot sales have gone stratospheric.

The advancing sex robot hordes leave so many issues to unpack, so many questions to answer. Why do they so often resemble young women? Can a robot give consent? Will sex with robots cause men to objectify women more than they already do? For a cracking read on the topic, I recommend Dr. Kate Devlin’s book Turned On, but many wonderful authors pose and answer these 21st Century dilemmas.

The issue I want to explore in this story is jealousy. How does the very idea of sex robots make you feel? That includes the thought of your lover getting with a robot and the idea of getting with one yourself.

I thought about this issue quite a bit while writing Artificial Intimacy, a book that involves several appearances by sex robots. Ever the scientist, I anticipated that robots would be perfect experimental apparatus with which to test a contentious idea about the origins of jealousy.

Hey jealousy

Jealousy’s bitter flavours can come from many different emotional ingredients, particularly sexual or emotional infidelity. Way back in 1992, Evolutionary psychologist David Buss proposed that women and men would emphasise the sexual and emotional components of jealousy somewhat differently. He asked heterosexual participants to conduct the following exercise in their imaginations:

Imagine your current lover having hot sex with somebody else.

Now clear your mind, and imagine your lover developing an intimate, loving bond with another.

Which scenario disturbed you more?

The hot sex scenario tended to disturb men more, on average, than women. Straight women report being more jealous than men do at the prospect of emotional infidelity a la the second scenario.

In reality, few women or men enjoy contemplating either scenario, and the green-eyed monster draws its destructive energy from threats of both sexual and emotional rivalry. But the balance of flavours, to borrow from the hackneyed lexicon of reality television chefs, tends to differ, on average, between women and men.

The results confirmed Buss’ predictions based on what the sexes risk losing. When a man shares one night of passion with somebody else, his partner doesn’t necessarily lose all that much. The bigger risk for her lurks in the prospect of her partner’s one-time thing turning into something more.

Throughout our evolutionary past, that ‘something more’ might have involved him leaving to take up long-term with a new lover. Alternatively, it might have meant him keeping a mistress, or bringing another woman into the household, sharing his love, time, and resources with her.

That’s not how it worked for our male ancestors, though. If a man’s female partner spent one night in another man’s arms — or even five furtive minutes in the bushes — she could, in theory, conceive a child by that other man. Insecurity about paternity runs very deep through the het-male psyche, perhaps because our ancestors could ill afford to invest time, money, and emotional capital in rearing another man’s child.

Men do also have plenty to lose when a female partner forms an emotional attachment to another man, especially if that attachment leads her to leave him and take up with the new guy. And, likewise, if emotional infidelity leads to sexual infidelity and thence to cuckoldry. But the size of the two risks is somewhat different for women and men.

This ‘sex differences in jealousy’ hypothesis neatly illustrates the power of evolutionary ideas to enhance the scientific understanding of human behavior. At the time, it was an original, unanticipated prediction. As the evolutionary psychologist David Schmitt put it,

Not a single psychologist had ever made that prediction before. Not one, ever. It took an evolutionary perspective to guide psychologists to predict men and women might get upset differently, based in part on their differing reproductive interests.

Over a hundred studies have tested the hypothesis in various ways. Overall, those studies reveal robust sex differences in romantic jealousy. Those differences pop up consistently in all societies and cultures where researchers have studied them, from Brazil to Japan and from the traditional cattle-herding Himba of Namibia to educated college students in the industrialised U.S.A.

More subtle than Mars and Venus

While average sex differences in jealousy embody consistent features of human nature, they overlap, with some men far more concerned about emotional than sexual infidelity and some women the reverse. And like most evolved human behaviours, jealousy proves fine-tuned to context. For example, jealousy besets less desirable men, men who are shorter than their partners, and men with high-status rivals more profoundly than men who have objective reasons to be more secure.

Buss’ many vocal critics find themselves bamboozled by jealousy’s context-dependence, by differences between societies and rapidly-shifting social norms. The size of the sex differences in jealousy does vary between places, but in ways that confirm, rather than refute the evolutionary logic of why people get jealous. When women can earn as much as men, they are less jealous, and also less judgy about promiscuity. When social norms do not expect men to invest much in their children, men can be distinctly chilled about their wives’ and girlfriends’ other lovers.

Evolutionary accounts of human behaviour often battle blustery headwinds of wishful thinking and obfuscation. Buss and the many researchers who have replicated his findings are often accused of claiming that men only care about sexual infidelity whereas women only care about the emotional kind. Au contraire, they lay a far more modest claim: that women and men can experience both flavours of jealousy, but because of the differences in evolutionary costs, the balance of those flavours differs, on average, between the sexes.

The deep evolutionary links between monogamy and fatherhood are more complicated than we thought

Enter the robots

Sex robots provide a chance to consider novel circumstances, with some of the cultural baggage stripped away. And so I was delighted to stumble across a study that tested jealous responses to the idea of sexual or romantic robots.

The study described two hypothetical robots and situated them in a fictional 2035. One, the Sex Robot, can learn a user’s sexual preferences and proclivities, and satisfy them thoroughly, but cannot form friendships or romantic relationships with a user. The other, a Platonic Love Robot can hold deep and meaningful conversations, building intimate friendship, and even love. But these Platonic Love Robots have no bodies, manifesting only as a microphone and a speaker.

The study sought to test how partnered heterosexuals anticipate responding to the two robot types. Admittedly, partnered people do not seem the obvious market for sex or intimacy bots. Given that many people fear being displaced from their relationships by such technologies, however, the research poses an intriguing question.

Like the study’s authors, I expected heterosexual men to be more jealous of their female partner being with a sex robot. In contrast, het-women wouldn’t want their male partners to own the intimacy bot.

Not so fast: women and men were equally jealous — and not very jealous at that — of the idea of their partner being with a Platonic Love Robot. Women and men were similarly disposed to the idea of such robots existing. The only difference that concerned the Platonic Love Robot was that women thought their partners wouldn’t mind them using one.

With Sex Robots, women and men differed quite a bit. Women disliked the idea of the Sex Robot, disliked the idea of their partner using one, and anticipated feeling jealous. They also thought their partner would be jealous of them using one.

The two hypothetical robots certainly got people thinking, but they didn’t confirm the theories about the evolution of jealousy. Perhaps we shouldn’t be surprised: human jealousy originates in a perceived threat from human rivals. Those rivals are capable of both love and sex, and of producing sperm, getting pregnant, or abandoning a mate. The hypothetical robots could only do the love or the sex, and nothing else.

The study, instead, neatly tests people’s attitudes to sophisticated sex toys. It may be too early to declare that adding a robotic unicorn to your relationship won’t create jealousy. People already treat even disembodied chatbots like Alexa as if they are real people. Will we invite robots into our beds and involve them in our relationships? And will the robots stir more substantial insecurities as they improve?