A philosopher argues that taking love-altering substances might not just be a good idea, but a moral obligation.

George Bernard Shaw once satirized marriage as "two people under the influence of the most violent, most insane, most delusive, and most transient of passions, who are required to swear that they will remain in that excited, abnormal, and exhausting condition continuously until death do them part."

Yikes. And yet, nearly all human cultures value some version of marriage, as a nurturing emotional foundation for children, but also because marriage can give life an extra dimension of meaning. But marriage is hard, for biochemical reasons that may be beyond our control. What if we could take drugs to get better at love?





Perhaps we could design "love drugs," pharmaceutical cocktails that could boost affection between partners, whisking them back to the exquisite set of pleasures that colored their first years together. The ability to do this kind of fine-tuned emotional engineering is beyond the power of current science, but there is a growing field of research devoted to it. Some have even suggested developing "anti-love drugs" that could dissolve abusive relationships, or reduce someone's attachment to a charismatic cult leader. Others just want a pill to ease the pain of a wrenching breakup.





Evolutionary biologists tell us that we owe the singular bundle of feelings we call "love" to natural selection. As human brains grew larger and larger, the story goes, children needed more and more time to develop into adults that could fend for themselves. A child with two parents around was privy to extra resources and protection, and thus stood a better chance of reaching maturity. The longer parents' chemical reward systems kept them in love, the more children they could shepherd to reproductive age. That's why the neural structures that form love bonds between couples were so strongly selected for. It's also why our relationships seem to come equipped with a set of invisible biochemical handrails: they're meant to support us through the inevitable trials that attend the creation of viable offspring.





The problem for us modern, long-lived humans is that natural selection is only interested in reproductive fitness. Once your kids can make their own kids, natural selection's work is finished. It doesn't care whether your marriage remains emotionally satisfying into your golden years. But if the magic of love resides in the brain, an organ whose mysterious workings we are slowly starting to unravel, there might be a workaround.





At first blush, love may seem like a poor prospect for pharmacological intervention. The reflexive dualist in us wants to say that romantic relationships are matters of the soul, and that souls ought to be free of medical tinkering. Oxford ethicist Brian Earp argues that we should resist these intuitions, and be open to the upswing in human well-being that successful love drugs could bring about. Over a series of several papers , Earp and his colleagues, Anders Sandberg and Julian Savulescu, make a convincing case that couples should be free to use "love drugs," and that in some cases, they may be morally obligated to do so. I recently caught up with Earp and his colleagues by email to ask them about this fascinating ethical frontier. What follows is a condensed version of our exchange.





What is the current thinking among evolutionary biologists as to how love---or adult pair bonding---evolved?

From the perspective of evolutionary biology, love is a complex neurobiological phenomenon that has been wired into us by the forces of evolution. It makes heavy use of the brain's reward systems, and its ability to bring together (and keep together) human beings--from prehistoric times until the present day--has played a major role in the survival of our species. In terms of natural selection, the working consensus among evolutionary biologists is that the human adult pair bond probably developed out of earlier structures involved in creating and sustaining feelings of attachment between mothers and their infants. Evolution likes to make use of existing systems for new purposes. In this case, the shift might have been driven by the heightened importance of paternal care for offspring with bigger and bigger brains over generations of human evolution. These burgeoning baby brains took longer to reach maturity than their more ancestral counterparts, leaving the infant vulnerable and underdeveloped for extended periods of time. The idea is that if parents fell in love and remained together during this fragile period for their offspring, their own genetic fitness would be enhanced.

The anthropologist Helen Fisher has famously argued that "love" is not a single straightforward emotion, but an emergent suite of motivational states that stem from underlying systems for lust, attraction, and attachment. In her theory--one of a number of "biological" theories of love with quite a bit of overlap between them--the lust system promotes mating with a range of promising partners; the attraction system guides us to choose and prefer a particular partner; and the attachment system fosters long-term bonding, encouraging couples to cooperate and stay together until their parental duties have been discharged. These universal systems are then hypothesized to form a biological foundation on which the cultural and individual variants of sexual, romantic, and longer-term love are built.

What scientific evidence do we have that the difficulties people face in modern relationships can be successfully addressed with pharmaceuticals?

Modern relationships are challenging for a whole range of reasons, and these reasons might be very different from one couple to the next. Drug-based treatments aren't always going to be the best approach, and sometimes they should even be avoided. Putting a chemical band-aid on a violent or abusive relationship, for example, would be an extremely bad idea. But we do know that in at least some cases, states of the brain that are susceptible to being pharmacologically altered may have something to do with the interpersonal difficulties couples face.

To give an obvious example, just think of a marriage in which one partner suffers from severe depression. As anyone who's been in that situation can tell you, chronic depression in one or both members of a committed partnership can drag the whole relationship down. Addressing the root of the problem, in this case through the use of anti-depressant pharmaceuticals if necessary, could make a big difference for some couples.

For another example, consider the widespread use of Viagra to treat male impotence, a problem that prevents some couples, especially older couples, from having sex. Lack of sex reduces oxytocin levels, and reduced oxytocin levels can degrade a couple's romantic bond. If a drug-based treatment could help the couple restore a healthy sex life, this could improve their chances of sustaining a well-functioning relationship.

Beate Ditzen and her colleagues at the University of Zurich have shown that oxytocin nasal spray can facilitate positive communication--and reduce stress levels--in romantic couples engaged in an argument. Oxytocin, sometimes called the "love hormone" for its role in sustaining mother-infant and romantic attachment bonds, increased the ratio of positive to negative communication behaviors and facilitated a drop in cortisol levels after the conflict. These factors have been shown to play a major role in predicting long-term relationship survival. While commentators like Ed Yong have recently emphasized that oxytocin can have a "dark side" as well--for example, by promoting in-group favoritism--the key is to figure out which people, which situations, and which ways of administering the hormone will maximize its effectiveness and minimize any troubling side-effects. We're working on some research right now to sort these conditions out.

In earlier decades, MDMA (ecstasy) was sometimes used in couple's therapy to boost empathy and improve emotional communication skills. While this sort of use would be illegal today, there has been a recent resurgence of scientific interest in possible therapeutic uses of MDMA, for example to treat Post Traumatic Stress Disorder. More research is needed, of course, but there is no reason why it should not be carried out, carefully and ethically, with proper social, procedural, and legal safeguards in place.

You argue that "love drugs" can help us address the tension between our moral values and our evolved psychobiological natures. Where does that tension manifest itself most obviously in relationships today? How have things changed since our basic sexual and relational drives evolved?

If you look at this in the context of evolutionary biology, you realize that in order to maximize the survival of their genes, parents need to have emotional systems that keep them together until their children are sufficiently grown--but, what happens after that is of no concern to natural selection. As Donald Symons has written, "in analyzing the psychological underpinnings of marriage [we should] keep in mind that Homo sapiens is the product of evolution ... we are designed to promote gene [survival], not individual survival, and reproductive [success], not marital success." Since we now outlive our ancestors by decades, the evolved pair-bonding instincts upon which modern relationships are built often break down or dissolve long before "death do us part."

We see this in the high divorce rates and long term relationship break up rates in countries where both partners enjoy freedom--especially economic freedom. We are simply not built to pull off decades-long relationships in the modern world. Nature designed us to be together for a while, but not forever--and once we push beyond the natural childrearing boundary, we are, in a sense, living on borrowed time.

Another major tension comes from our non-monogamous impulses. Humans are rare among mammals in that we practice at least some form of social monogamy. But there is a mountain of evidence suggesting that sex outside of the primary parenting bond was common throughout our evolutionary history, and would have been to the reproductive advantage of both males and females of our species. Jealousy seems to have deep roots as well, so there is nothing particularly new about feelings of sexual possessiveness--but the conscious, socially enshrined value-expectation that both husbands and wives should remain 100% sexually exclusive to one another for decades in a row, and that failure to meet this goal should entail the end of the relationship, is certainly a more recent invention. Adultery is one of the leading causes of marriage failure.

You point out that married couples should have the freedom to use love-enhancing drugs if they so wish, but you also go a step further, arguing that there are circumstances where married couples ought to take them. What are the most compelling of those circumstances?

Imagine a couple that is thinking about breaking up or getting a divorce, but they have young children who would likely be harmed by their parents' separation. In this situation, there are vulnerable third parties involved, and we have argued that parents have a responsibility--all else being equal--to preserve and enhance their relationships for the sake of their children, at least until the children have matured and can take care of themselves. One way to do this, of course, would be to attend couple's therapy and see if the relationship problems could be meaningfully resolved through "traditional" methods. But what if this strategy isn't working? If love drugs ever become safely and cheaply available; if they could be shown to improve love, commitment, and marital well-being--and thereby lessen the chance (or the need) for divorce; if other interventions had been tried and failed; and if side-effects or other complications could be minimized, then we think that some couples might have an obligation to give them a try. Of course, we aren't suggesting that anyone should be forced to take love drugs--or any drugs--against their will. But we do think that when children are involved, the stakes become higher for finding a workable solution to relationship difficulties between the parents.

What if "love drugs" only serve to prop up fading cultural institutions? Some might argue that monogamy is outdated, or a bad fit with human nature, and that rather than pharmacologically altering ourselves to accommodate it, we should jettison the whole thing instead. What would you say to them?

Whenever individuals--or societies--experience a mismatch between their values and human nature, they face a choice. They can give up or amend their values, accept a contradiction between their values and their impulses or behaviors, or they can try to modify or manage human nature.

This "management" can happen in different ways. It might involve shaping the physical, social, and legal environment to incentivize value-consistent behavior and disincentivize value-inconsistent behavior. Or it might involve the use of biotechnology (such as love drugs in the case of monogamy) to modify the source of the behavior directly--or some combination of the above. Which course to take for any given mismatch depends upon a huge range of factors, and there are often good arguments for different approaches depending on the details of the given case.

As a baseline, we have argued for something called the "principle of default natural ethics." This just means that, given the choice, we should try to adopt values that are as consistent as possible with human nature, so that we can avoid troubling side-effects that come from unnatural suppression and heavy-handed regulation of basic instincts: just think of the recent sex abuse scandal in the Catholic Church, and consider some obvious reasons why that tragedy might have come about. Sometimes, following the principle of default natural ethics means that we should jettison our social institutions--especially when they are so far out of synch with our human dispositions as to be totally unworkable, or when they end up creating bigger problems than they were designed to solve in the first place. This is probably part of the reason why we've moved past communism as a model for social and political organization: it seemed, at least to many people, to make a lot of sense on paper, but in the real world it ran up against too many deep facts about the way that people actually work.

But communism was an experiment, both radical and recent. Monogamy, on the other hand, or at least some form of it, has been a part of human societies for a much longer time, so we have to be more careful about how we deal with its problematic features--most notably the gap it creates between the ideal of sexual exclusivity and the reality of human promiscuity.

Some people think that we should give up on monogamy, and there are plausible arguments for this view. In fact, one possibility is that love drugs could be used to eliminate jealousy rather than the impulse to stray--and for individual couples, this might indeed be a worthwhile strategy. For couples who are committed to polyamory, for example, jealousy would seem to be the odd man out: it conflicts with the polyamorists' higher-order goals for sexual openness.

We obviously cannot set the moral priorities for any given relationship. But in making a more general argument, we note that most couples as a matter of fact value sexual fidelity and make an explicit promise to hold to it. And at least when children are involved, we think that this promise may be morally justified, since extramarital sex can lead to extramarital love that would divert time and energy directly away from existing offspring. On the other hand, when children are not an issue, when there are good arguments for non-monogamy for a particular couple, or when non-monogamous social institutions have a good chance of contributing to human welfare in a given culture or community, then we don't see any reason why people should go out of their way to "prop up" problematic social norms through the use of pharmacology.

There are certain environmental features of modernity---like ease of travel and expanded social circles---that make monogamy more difficult. Why shouldn't we focus on limiting the effects of those factors instead of altering ourselves biochemically?

It's a question of trade-offs. Most people think that ease of travel and far-flung social connections are a good thing, and contribute positively to human flourishing in the modern era. On a practical level, too, these things aren't likely to go away. So when they do become a problem--by making it easier to commit adultery, for example--we have to be creative about how we respond. Certainly there are a range of non-biochemical strategies that couples can use to stay faithful to each other despite the pressures and temptations of modern life, and they should be free to pursue these strategies to the best of their abilities. We have simply argued that it may be time to consider a wider range of possibilities, as contemporary relationships need all the help they can get. At the end of the day, anyone who fully appreciates the post-Enlightenment ideals ensconced in present-day Western cultures would be loathe to restrict travel, freedom of socializing, freedom of divorce, or gender equality in the workplace, despite their potential to undermine full-fledged monogamy. The cure would be worse than the disease.

You could see how these drugs could be used in the context of a parent-child relationship---perhaps to boost feelings of love in an otherwise apathetic mother. Are there any special ethical concerns there?

There may be some. But remember our analogy to treating depression in a romantic context, and then just extend this reasoning to a parent-child relationship. So long as it is the parent taking the drug, voluntarily and under conditions of informed consent, and so long as this drug-based treatment had a reasonable chance of improving her ability to care for her own offspring, there would seem to be little to worry about in terms of ethics. Some people might be concerned that this drug-induced "love" would be inauthentic in some way - but it depends on what you take as your baseline. Perhaps the authentic situation is the one in which feelings of love and contentment occur naturally between the parent and the child, and it is only a disordered biochemical state that brought about the apathy actually felt by the mother. Just as when a depressed person finds that a small dose of medication allows him to "be himself" again--finding joy in the old activities he used to love so much, for example--so might some mothers find that taking a love drug allows them to engage with their children in a way that feels more true to their own self-conception than they would feel without it.

It's often said that you don't have an obligation to love someone, usually based on the idea that it is impossible to voluntarily control our emotions. But if love drugs make such control more possible, then there might be some loves that should be felt. It's debatable whether this is true for spouses, but it seems very hard to argue against the idea that we should love our children.

You've also written about "anti-love drugs," which could be used to dissolve love bonds in abusive relationships, or in cases where someone has fallen under the spell of a cult leader. Are there drugs like this that are currently under development?





With the exception of anti-androgen drugs sometimes used to treat paedophilia--and which work in a rather "low-level" way by targeting the bodily sex drive--very few chemical substances are currently available that have been explicitly designed with the goal of diminishing feelings of love or sexuality. But that doesn't mean that anti-love drugs don't exist in certain forms. Some Orthodox Jewish groups use "off label" anti-depressant medication to suppress libido, so that young yeshiva students can comply with strict religious norms concerning human love and sexuality. These selective serotonin re-uptake inhibitors (SSRIs) can also lead to "emotional blunting" of higher-order feelings involved in romantic attraction. Some people report finding it harder to cry, worry, get angry, or care about other people's feelings while taking anti-depressants. The overall lack of emotional stimulation produced by SSRIs has been described as producing a "blandness" that can overwhelm certain romantic relationships. As one author has put it : "aside from ruining your sex life, antidepressants could also be responsible for breaking your heart."





Other substances that can reduce libido--usually considered a "side effect"--include tobacco and alcohol, almost all blood pressure pills, certain pain relievers, statin cholesterol drugs, some acid blockers used to treat heartburn, the hair loss drug finasteride, and seizure medications including gabapentin and phenytoin.





There is some work showing that scientists can block a pair-bond from forming in certain vole species--those cute little rodents than are one of the few socially monogamous creatures on the planet--but this involves injecting dopamine- or oxytocin-blockers directly into the nucleus accumbens, and so similar experiments have not been carried out in humans.

In some cases---as with someone under the spell of a cult leader---the drugs would conceivably be administered against the wishes of the smitten person. How do we justify an invasion of autonomy that goes to something as personal as love?





This is a tricky situation. On the one hand, if love really can make a person "lose her mind" then at least in theory there could be an argument for saying that a person has been compromised mentally and thus some form of intervention could be justified. You would have to provide very strong evidence that the person was genuinely incompetent to make a decision on her own behalf, and you would have to be sure that she was at risk of suffering serious and unambiguous harm if left to her own devices. But the potential for paternalistic overreach here is huge, and we should be very cautious about assuming that we know better than someone else what is in her own best interests, all things considered. In general, individuals should be protected from any form of coercion by ensuring there are robust laws protecting independence of the mind. Interestingly, small children can be indoctrinated into fundamentalist religious cults without any restriction. That is a lot more worrying and occurs for thousands, or perhaps millions of children.





What's the threshold for the use of anti-love drugs? Should people use them in cases where they aren't in any particular danger, like in the case of a tough break-up? Some might argue that you can't learn from a break-up without experiencing it in full. Do you buy that?





In a forthcoming paper, we argue for four conditions for the use of anti-love biotechnology: (1) the love in question is clearly harmful and needs to dissolve one way or another; (2) the person would conceivably want to use the technology, so there would be no problematic violations of consent; (3) the technology would help the person follow her higher-order goals instead of her lower-order feelings; and (4) it might not be psychologically possible to overcome the relevant feelings without the help of anti-love biotechnology. But the question here seems to be, what if it were possible to overcome the attachment, only it would involve a lot of protracted pain and difficulty, and the person would rather just move on with the business of living?





Philosophers will disagree about what should be allowed in a case like this. So-called "bioconservatives" would probably remind us that even great and seemingly unbearable suffering can impart unforeseeably important lessons, and that people should be very careful about turning to drugs to solve their problems or dull their pains. They tend to say things like: "With suffering comes understanding" - and of course, there is a kernel of truth to that. Bioliberals, on the other hand, would be likelier to point out that "traditional" methods of getting over heartache aim at changing our brain chemistry just as much as drugs would, only indirectly and sometimes less effectively. "Sometimes suffering is just suffering," they would add, and then they might go on to suggest that such fruitless pain should be eliminated by whatever means the individual judges for himself are best.





For our part, we certainly don't deny that there can be great value in experiencing the world "as it really is" - in its heartbreak and agony as much as in its joys. But we think that even if it could be shown that human beings had some sort of existential duty to experience pain along with happiness, this duty would not absolute: it could be trumped by the debilitating effects of certain traumas, and sometimes a broken heart might qualify in just this sense.





What if these drugs enabled romantic sabotage? You could envision a scenario where someone uses a discreetly delivered anti-love drug to ruin someone else's relationship---in order to get rid of a romantic rival.





This would clearly be unethical, and would be analogous to (and perhaps no worse than) telling a scurrilous lie about the mutual object of affection in order to cause the rival-in-love to lose his interest. It also calls to mind the use of "date-rape" drugs to manipulate a person into having non-consensual sex. In general, if the love- or sex-related action would be considered morally impermissible if undertaken by "traditional" means, then it should be considered morally impermissible if undertaken by means of anti-love biotechnology. We need robust laws to prevent anyone's giving a drug or other intervention to another person that could alter their minds or change their behavior without their consent. This will be a big area in the future. Love drugs are just one part of it.





One worry with "anti-love drugs," is that they could be used by fundamentalist groups to "cure" homosexuals, or by traditionalist groups in India that disapprove of "inter-caste love." Do these risks negate the potential social utility of anti-love drugs.





This is an important consideration. As is well known, the very disturbing practice of conversion therapy in the United States (designed to "cure" gay and lesbian individuals of their sexual and romantic feelings) carried on until at least the 1970s with the full-throated endorsement of the mainstream profession of mental health. And as late as 2012, a U.S. federal judge ruled that such therapy cannot be outlawed, even when conducted on minors, since it constitutes a protected form of religious "speech"-- indeed it is still being performed in a number of fundamentalist Christian communities to this day.





While there is very little evidence that existing interventions actually work in the way intended--and quite a bit of evidence that they can cause trauma and other serious harms--future technologies might indeed be more effective. So if we were to grant that religious fundamentalists (for example) might try to use these future technologies in ways that progressive-minded people would object to, one tempting conclusion is that we should try to prevent their coming-into-being at whatever cost.





But jumping to this conclusion would be premature. In the first place, we have to remember that any new technology poses risks - whether it is an anti-love pill, a powerful military weapon, or something more mundane. So the possibility that a new technology might be used for ill can never constitute, by itself, sufficient reason to reject it. Instead, the potential harms that might accrue from misuse of the technology have to be weighed against the potential benefits that might accrue from its responsible use. Second, even if it could be shown that the development of various anti-love interventions would be too risky to be worth pursuing, it still might not be possible to avoid having to deal with their eventual existence. This is because advances in other areas - i.e., in treatments for debilitating mental disorders such as autism - might leave us with the very same neuroscientific knowledge and technological capabilities that we would have ended up with had we sought them out for love-diminishing purposes directly. In such a scenario, we would still have to ask ourselves whether or when to use the powers we had (inadvertently) created.





What this question highlights, though, is that ethical dilemmas concerning emerging biotechnological innovations cannot be resolved in an "enlightened" academic vacuum. Instead, there is a much wider debate taking place in society over what sorts of values we should hold in the first place with respect to things like love, sex, and relationships (and nearly everything else as well). And plainly this broader conversation--between the insights of progressivism and the insights of conservatism, as well as between the forces of secularism and the forces of religion--will continue to shape the moral ends toward which human beings collectively and individually strive, regardless of what technology is actually in hand, and regardless of what pontificating bioethicists may argue in their papers. So we have argued that at most fundamental level, the relevant question--what we call the basic technology-value question--becomes:

How can we use new technologies for good rather than for ill, while simultaneously trying to reach a functional consensus on what sorts of things should be considered good, and what sorts of things should not be considered ill?



'Progressive-minded people' clearly have their work cut out for them in terms of this longer-term project.







