Could we create a "morality pill"? Once the stuff of science fiction, recent studies in neuroscience have shown that brain chemicals can subtly influence some aspects of moral judgments and decisions. However, science is very far from creating pills that can turn sinners into saints, as I have argued many times before. So imagine my surprise when I came across the headline, “‘Morality Pills’ Close to Reality, Claims Scientist”– referring to a lecture I gave recently in London. (I asked the newspaper where the reporter got his misinformation, but received no response to my query.)

Sensationalist reports like this are not only inaccurate, but also neglect the rich complexities of the brain that make neuroscience so fascinating. It is these same complexities that will make it very difficult for scientists to develop a morality pill.

First, let’s consider the evidence that drugs can influence morals. Laboratory studies typically compare the effects of a placebo pill with those of a drug treatment that alters the function of a specific brain chemical. After taking either the drug or placebo, healthy volunteers make a series of moral decisions or judgments. For example, they may consider whether to donate to charity, or cooperate with others, or judge whether it is permissible to harm one person in order to save many others. The key question is whether the drug alters people’s decisions and judgments, relative to placebo.

A few years ago my colleagues and I investigated how the brain chemical serotonin influences moral judgments of right v wrong. We gave healthy volunteers either placebo or the serotonin-enhancing drug citalopram, and examined their judgments in a series of moral dilemmas such as the classic “trolley problem”:

A trolley is out of control and is headed toward five workers on the tracks, who will die if you do nothing. You and a fat man are standing on a footbridge over the tracks. If you push the fat man off the footbridge onto the track, his body will stop the trolley, killing him but saving the five others. Is it morally acceptable to push the fat man?

﻿After taking citalopram, most people thought it was worse to push the fat man, compared with when they took the placebo. So could citalopram be a morality pill?

It depends on whom you ask. The trolley problem does not have a universally accepted “right” answer. Rather, there are two schools of moral thought that take opposing views. Consequentialists (like Jeremy Bentham) advocate for actions that produce the best overall outcome, and thus support killing one to save five. In contrast, deontologists (like Immanuel Kant) argue that certain actions, such as killing an innocent person, are forbidden and so frown upon killing one to save five. So deontologists might consider citalopram to be a morality pill, but consequentialists would likely disagree.



Another recent study examined how the anti-anxiety drug lorazepam influenced moral judgments in the trolley problem. This drug had the opposite effect of citalopram: after taking lorazepam, people were more likely to approve pushing the fat man. So could lorazepam be a morality pill? Again it clearly depends on whom you ask – but this time it’s consequentialists who might be keen to pull out the prescription pad.

The debate between consequentialists and deontologists has persisted for hundreds of years, and is unlikely to be resolved any time soon. This is the first major obstacle facing the development of a morality pill: until we can agree on what is moral, we won’t agree on what kinds of behaviors to target with a pill.

Another brain chemical that influences social behaviour is oxytocin. Some call it the “love hormone”, “moral molecule”, or “cuddle chemical”, based on studies showing that boosting oxytocin enhances empathy, trust, generosity and cooperation.

So could oxytocin be a morality pill? Not so fast. Oxytocin’s catchy nicknames belie some of its more sinister effects on behaviour. For example, oxytocin increases envy and schadenfreude, makes people more likely to favour members of their own group over those in other groups, and can increase people's dishonesty when lying benefits their team. Herein lies the second major obstacle for morality pills: most brain chemicals influence a diverse range of behaviours. Drugs that target these chemicals will therefore have a variety of effects, some good, some bad (and of course what counts as good or bad depends on whom you ask – see obstacle #1 above).

Many of the drugs I’ve mentioned here are widely prescribed to people suffering from mental illness. Does that mean we should be worried that people who take these drugs will experience changes in their morals, or even their personality?

Several points are important to bear in mind here. First, the studies showing effects of drugs on moral decision-making were carried out in healthy volunteers, whereas drugs are prescribed to people suffering from mental illness. The brains of people with mental illness may respond differently to drugs than do the brains of healthy volunteers. So it’s not at all straightforward to generalise from studies carried out with healthy volunteers to effects on people taking drugs for medical reasons.

Furthermore, the drug effects in these studies are generally very subtle. Imagine you have to rate the acceptability of pushing the fat man on a scale from 1 ("completely unacceptable") to 10 ("completely acceptable"). If you would normally give a score of 4, taking citalopram might push you towards a 3. So although studies have shown drugs can reliably shift people’s judgments, the effects are not large enough to induce dramatic changes in personality.

That’s not to say that subtle drug effects on behaviour aren’t potentially important, particularly when aggregated at a large scale. And we have learned a great deal about the neural basis of morality by investigating how drugs shape moral behaviour. But let’s be clear that morality pills are not likely to appear at your local pharmacy any time soon.