Donald Trump wants to be the Republican Party’s presidential candidate for the November 2016 election in the US. But even before he has won the party’s nomination, top American psychologists compares the billionaire to three dictators. They are deceased Libyan strongman Muammar Gaddafi, French military leader Napoleon Bonaparte and Iraqi dictator Saddam Hussein.

All three are feared dictators and narcissists. Likewise, Trump is a "textbook" narcissist, and if wins the Republican nomination and the presidential election, the real estate mogul would make a dangerous world leader, reports Rawstory. The danger, explains clinical psychologist George Simon to Vanity Fair, is “when a narcissist is given immense power over people’s lives, they can behave much differently.”

If Trump wins, Simon warns that as president, he would shush dissenters, refuse to compromise and oppress certain group. Even in his campaign, Trump has spoken negatively against Mexican and Syrian migrants, who would likely bear the brunt of his ire if he replaces the outgoing president, Barack Obama.

Narcissists are characterised by lack of empathy for others, deep need for admiration and inflated sense of importance, according to Mayo Clinic. Narcissism is a mental disorder.

His lack of empathy is visible in Trump’s generalisation of Mexican migrants as criminals, drug dealers and rapists. Trump has also promised to close the gate on Muslim migrants, which again demonstrates his lack of empathy since most of the asylum seekers, although followers of the Islam religion, are refugees fleeing dictators.

Simon likewise points to Trump’s personal attacks on Fox News host Megan Kelly when he called her a bimbo and said blood was coming out of her eyes after Kelly, who moderated the Republican debate, said she may have overestimated his anger management skills.

But experts point out that what made Trump a successful businessman and reality TV star makes him a potentially dangerous political leader. They compare Trump to Gollum from “Lord of the Ring” who sees the presidency as the “one ring to rule them all.”

It is not just American neurologists who have observed Trump’s quirky behaviour. Over 570,000 Britons have signed an online petition to ban the presidential aspirant from entering the UK over his comments about Muslims and Mexican immigrants. On Monday, British MPs spent three hours debating on the proposed ban.

While for neuroscientists Trump is a narcissist and potential dictator, to British MPs, he is an attention seeker, fool, buffoon, demagogue and wazzock, which is a British slang for stupid or annoying person.