Why all of us are evil

If you’ve ever fantasised about throwing your boss out of the window, read on. Dr Julia Shaw discusses the science that shows we’re all capable of murderous thoughts, and calls time on everyday evil.

Words by Julia Shaw

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Photograph of a coloured lithograph showing a withered tree bearing apples labelled with sins; representing the life of sin c. 1870, after J. Bakewell.
The Tree of Death, Thomas S G Farnetti. Source: Wellcome Collection. Attribution 4.0 International (CC BY 4.0).

Have you ever fantasised about murdering someone? When psychological scientists Douglas Kenrick and Virgil Sheets at Arizona State University asked participants whether they had ever had a murder fantasy, 73 per cent of men and 66 per cent of women said yes.

They were surprised by these results and replicated the study. The second time they got similar results: 79 per cent of men and 58 per cent of women said yes. The most popular targets for men were strangers and co-workers, while women preferred family members. Evil stepparents were also fantasy victims, bringing to mind a horror-movie version of ‘Cinderella’.

The fact that most people who have murder fantasies never go through with them begs the question: why do we have them in the first place? Evolutionary psychologists including Joshua Duntley and David Buss have argued that murder fantasies help us play out hypothetical scenarios, which allows us to make better decisions in the future. Fantasising lets you realise that you don’t actually want to murder your boss – there are just too many bad consequences.

The science of trolleyology

It’s not just in our own heads that playing out hypothetical scenarios can be helpful. Psychologists and philosophers have long used hypotheticals to better understand how people think they would, or should, act. One of the most famous of these involves a series of ethical dilemmas where the task is deciding who to murder (or let die).

This is the trolley problem, typically credited to philosopher Philippa Foot in 1967. The study of ‘trolleyology’ has taught us a great deal about how people make difficult ethical decisions.

More: Public morgues were all the rage in 1800s Paris.

Here is the general scenario: a trolley is running out of control down a railway track. In its path are five people who have been tied to the track by a madman. Fortunately, you can flip a switch that will lead the trolley down a different track. Unfortunately, there is a single person tied to that track. Would you flip the switch?

This might seem familiar. Perhaps one of the best-known moral philosophers of our generation is the fictional Chidi from the American TV series ‘The Good Place’. In an episode that goes surprisingly deep into ethics, the trolley problem is brought to life.

Moral philosopher Chidi experiences the trolley problem like never before in ‘The Good Place’.

Chidi is transported into a trolley, and is forced to be the driver. He immediately becomes paralysed by the reality of having to make a decision on the spot, and lets the trolley kill five construction workers, getting splattered with their blood in the process.

Chidi’s nightmare experience shows in gory detail how difficult it might be to translate what we think we are going to do into what we actually do.

Scientific studies that ask participants to think through the task, or experience the situation in virtual reality, show that we typically think that the decision here is easy. When we are faced with impersonal dilemmas like this, most of us become utilitarian. We save the five and sacrifice the one. Our mantra is “the greatest good for the greatest number”.

But this changes as soon as we make the situation personal.

How selfish emotion fights practical logic

Three small but significant modifications to the trolley problem are likely to change your answer completely.

First, what if you had to get physical? Instead of using a lever, you had to push a man off a bridge to stop the train from killing five people.

Second, what if the person was related to you? Would you be willing to sacrifice your own child? Or grandma?

Finally, what if the person you had to sacrifice was yourself?

Photograph detail of a coloured lithograph showing a withered tree bearing apples labelled with sins; representing the life of sin c. 1870, after J. Bakewell.
The Tree of Death, Thomas S G Farnetti. Source: Wellcome Collection. Attribution 4.0 International (CC BY 4.0).

This ‘Tree of Death’ features ‘evil fruit’ labelled with things like murder, incest and extortion. There are also things we might not necessarily class as ‘evil’ today, such as scoffing at religion, back-biting and love of the world.

As I discuss in my new book ‘Making Evil: The Science Behind Humanity’s Dark Side, neuroscientist Joshua Greene and colleagues have studied what moral decision-making looks like in the brain and they have found that emotion plays a huge role, changing the way we mentally deal with this kind of dilemma.

When we are making moral decisions purely based on logic – on what Greene and his colleagues call “controlled cognitive processes” – we are more likely to make utilitarian decisions that maximise the greater good.

However, “automatic emotional responses”, like the emotions that go along with the thought of having to kill someone or losing a daughter, can hijack this process. This emotional interference means we are far more likely to make selfish judgements. Rather than weighing up killing five people against killing one, we weigh up the emotional impact on ourselves of killing our own daughter or letting five strangers die.

Or, like our fictional moral philosopher Chidi, our automatic emotional responses can shut us down entirely, so we let the default outcome happen. Either way, we have blood on our hands.

Our capacity for everyday evil

We need to be careful not to shroud our selfishness with a veil of morality. We can all make decisions that are unethical in the eyes of others, and we are all capable of doing or becoming what others might label ‘evil’. We might save our own child while sacrificing another’s, or save our own life while letting a whole building burn down.

Sometimes we say that someone is “just evil” as a way of avoiding thinking about what led them to do the thing that we think is so terrible. That’s not helpful, though. The capacity for great harm lies in every one of us, and we need to constantly and actively evaluate what the best course of action is – for others and for ourselves.

When we start making a decision, we must try to question our instincts and recruit our prefrontal cortex (which helps us regulate emotions and inhibits impulsive behaviour) to help us make more weighted decisions that include long-term planning. It’s more work, and our brains may fight us, but it’s likely to make us all better people when things get rough.

It is time to inform and empower ourselves in order to understand what leads to harm and how we can begin to fight against it.

It’s time to rethink evil.

About the author

Photograph of Julia Shaw

Julia Shaw

Dr Julia Shaw’s book ‘Making Evil: The Science Behind Humanity's Dark Side’ is out now. Dr Shaw is a psychological scientist based at UCL who is best known for her work in the areas of memory and criminal psychology. Her bestselling debut book ‘The Memory Illusion’ has appeared in 20 languages. She also co-founded the memory science and artificial intelligence start-up Spot, which helps combat workplace harassment and discrimination.