FOR THE PAST seven years I have been researching the influence of dangerous personalities on politics for my new book Disordered Minds.

What I discovered is that not only do positions of power appeal to individuals with dangerous personalities but the conditions that enable them to gain power, such as inequality and xenophobia, have re-emerged today with a vengeance. As a result, dangerous minds are increasingly ruling our world.

So, what are dangerous personality disorders?

While psychologists recognise several disorders that can result in dangerous behaviour, I have concentrated on three particularly dangerous conditions – psychopathy, narcissistic personality disorder and paranoid personality disorder. The core feature of psychopathy is an absence of conscience.

Desmond Tutu remarked that a person is a person because they regard others as persons. The cognitive and emotional functioning of psychopaths, however, is such that they see little or no distinction between people and things and are therefore unable to see others as persons.

Lacking any trace of empathy, they can commit violence of fraud without remorse. People with narcissistic personality disorder are characterised by their rigid belief in their own superiority. Individuals with this disorder crave constant attention and adulation. They treat others with disdain and are cognitively incapable of conceiving of the idea of equality, a concept they find intolerable.

People with paranoid personality disorder live in a constant state of hyper-attentive paranoia and regard everyone around them as a potential threat. In politics, individuals with this disorder typically scapegoat minorities, who they depict as an existential threat to society.

How do people with these disorders come to power?

Under certain circumstances, people with dangerous personalities have a greater chance of gaining power than those with normal psychology. In violent situations, such as revolution or civil war, for example, the ruthlessness of psychopaths is a distinct advantage.

Journalist Jason Stearns has described violence as being akin to a centrifuge that rapidly spins out of control, throwing reasonably minded leaders to the margins and leaving only the most callous at the centre of power. Such was the case with Hitler, Stalin, Mao, and Pol Pot. The rise to power of each of these tyrants was enabled by widespread violence and the social disintegration of their respective societies.

But it is not only violence that can allow leaders with dangerous personality disorders to come to power. As the election of Donald Trump in the US and the rise of xenophobic populism across Europe attests, we are currently living in conditions that enable politicians with dangerous personalities to gain widespread support.

The toxic triangle is an idea in political science that can help us understand why this is happening. The triangle consists of a dangerous leader, a critical mass of core followers, and the conducive environment that enables the leader’s rise.

Today’s political environment is characterised by the memory of a financial crash in which the perpetrators largely walked free; the cumulative effects of a decade of austerity when the consequences of the crash were shifted onto ordinary workers; stagnant wages and growing inequality; terror attacks by Islamic extremists; and large numbers of refugees fleeing war in Syria, Afghanistan, Iraq and beyond.

The mix of anger and fear that these conditions have created are providing the perfect environment for toxic leaders to gain power by stoking fears and promising easy solutions.

But it’s not just them, it’s also us.

The rise of pathological individuals to power cannot, however, be put down simply to the psychology of those with these disorders; it is also crucially about the psychology of the rest of us. People with dangerous personalities can have a powerful appeal for many normal people.

Freed from anxiety, self-doubt, and guilt, they strike many of us as having qualities we ourselves would like to possess. They ‘say what they think’, ‘they get things done’, ‘they do what they like’ and ‘don’t care what others think’.

The attraction which pathological individuals hold for many of us means that not only do we fail to recognise these most dangerous of personalities, but we often willingly place power in their hands.

What can we do?

In her book on Stalin’s Gulag, Anne Applebaum wrote, ‘This…was not written “so that it will not happen again”, as the cliché would have it. This…was written because it almost certainly will happen again.’ As Applebaum recognises, the seizure of power by pathologically disordered leaders is not an aberration. Sadly, it has been the norm throughout history.

The strongest protection against dangerous personalities is also the most logical – to ensure that individuals with dangerous disorders do not achieve positions of power.

As I argue in Disordered Minds, democracy provides our surest defence against dangerous political leaders. Electoral democracy provides the opportunity to keep dangerously disordered individuals out of power and to remove them from power once their destructive nature has become apparent.

Social democracy can be strengthened to limit social inequality and avoid the type of social breakdown that propels tyrants to office. And legal protection for human rights provides safeguards for every citizen against arbitrary abuse of power and the persecution of minorities by the majority.

As political scientist Ronald Inglehart has written, democratic institutions do not guarantee that the people will elect wise and benevolent rulers, but they do provide a regular and nonviolent way to replace unwise and malevolent ones. And the institutions of democracy place stringent limits on the actions of malevolent leaders during the time that they are in power.

At the launch of Disordered Minds in the Science Gallery last week, in my discussion with clinical psychologist Paul D’Alton, Paul talked about the civilising effect of conversation when such conversation is held in the context of respect and equality.

Democracy allows at least the possibility of civilising conversations being the basis of deciding how we are to live together as a society. With democracy now facing its worst crisis in half a century, it is up to all of us to value and strengthen our democracies. If we don’t, those civilising conversations could soon be replaced by the enforced silence of authoritarianism alongside the shrill cries of hate.

Ian Hughes is a scientist and author. His new book Disordered Minds: How Dangerous Personalities are Destroying Democracy is now available.