A pint-sized bully who loved to pull girls’ hair and once lobbed rocks at a toddler in his playpen. A loud-mouthed classroom know-all who could never admit he was wrong and boasted of giving the music teacher a black eye. And a sporting show-off who yearned to hear the crowd’s applause . . . but who would smash his baseball bat in fury if he didn’t win.

Arrogant, over-bearing, thin-skinned, determined, and not exactly great with the ladies — does this portrait of a child growing up in Fifties surburban New York sound like a certain grown-up (well, sort of grown-up) currently strutting the world stage?

It was Aristotle who said ‘Give me the child until he’s seven and I will show you the man’, and Donald Trump, now 70, would certainly agree. The 45th U.S. President insists he’s much the same character now as he was when he was in junior school.

According to Trump Revealed, a new biography compiled by Washington Post journalists who spoke to dozens of people who knew Trump as a child, he’s not wrong. The psychological resemblance is uncanny, and not a little disconcerting.

Angelic: But little Donald Trump would soon go on to become quite the bully

Trump Revealed is a new biography compiled by Washington Post journalists

Born in June 1946, Trump was the fourth of five children to Fred Trump, a ruthless Queens builder and property developer, and his Scottish-born wife, Mary, an immigrant who had fled poverty on the Isle of Lewis and met Fred at a dance in New York. Trump Sr was a dour, authoritarian patriarch who dressed in a jacket and tie even at home.

A workaholic, he was already very rich by the time Donald arrived. They lived in a 23-room, red-brick, mock Georgian mansion in the well-to-do Jamaica Estates neighbourhood of Queens.

They were the envy of their neighbours with a chauffeur, cook, colour television, intercom system and two Cadillacs with consecutive personalised number plates (virtually nobody had one back then but, of course, the showy Trumps had two).

Donald — with his ten-speed Italian racing bike and a huge, elaborate model train set — made the local children green with envy.

He clearly left an impression on his neighbours, classmates and teachers because so many could remember at least one chilling anecdote about him 60 years later.

When a ball bounced into their garden, he threatened to tell his father and the police about those responsible.

Dennis Burnham, who lived next door, was a toddler when his mother briefly put him in a playpen in their garden. She returned a few minutes later to find the current U.S. president, then aged five or six, standing at his fence throwing rocks at the little boy.

His mother warned Dennis to ‘stay away from the Trumps’ as they didn’t want him ‘beaten up’ by the family bully.

Another local child, Steven Nachtigall, now a 66-year-old doctor, said he never forgot Trump, a ‘loudmouth bully’, once jumping off his bike and pummelling another boy.

The disturbing image remained in his brain decades later, he said, because ‘it was so unusual and terrifying at that age’.

The 45th U.S. President insists he’s much the same character now as he was when he was in junior school

A Facebook posting on Donald Trump's page: '#TBT With my family growing up- I'm on the left'

Young Donald — whose nicknames at school included Donny, The Trumpet and Flat Top (for the blond pompadour hairstyle he had even as a child) — picked mercilessly on his own little brother, Robert, a quiet and sensitive child.

The future property tycoon later liked to boast how he once stole Robert’s building blocks and, so pleased with what he built, glued them together so his brother could never use them again.

Bullies are usually cowards, but Donald had a gutsy side. Former babysitter Frank Biggs recalls taking the five-year-old to explore a sewer pipe that was being built in the neighbourhood.

To his amazement, as dusk fell, the child followed him into the darkness without flinching.

A portrait of Trump in 1983

With his siblings, Donald went to a smart private primary school called Kew-Fores, where he quickly became notorious for being unruly, going around with a gang of boys who pulled girls’ hair and talked during class.

‘He was so headstrong and determined,’ recalled former teacher Ann Trees. ‘He would sit with his arms folded with this look on his face — I used the word surly — almost daring you to say one thing or another that wouldn’t settle with him.’

It’s an image that anyone who saw one of the 2016 Republican presidential debates can easily imagine.

Ditto, a former classmate, recalled a boy who would never admit he was wrong, no matter how trivial the subject. ‘He had a reputation for saying anything that came into his head,’ he added.

Trump spent so much time in detention that the punishment was nicknamed ‘DT’ in his honour.

When he was seven, he yanked classmate Sharon Mazzarella’s pigtails. She chased him downstairs and smashed him over the head with her metal lunchbox.

Trump admits he was a troublemaker at primary school. ‘I liked to stir things up and I liked to test people,’ he said years later. ‘It wasn’t malicious so much as it was aggressive.’ Trump bragged for a long time that, aged eight, he almost got expelled for giving his music teacher a black eye ‘because I didn’t think he knew anything about music’.

Born in June 1946, Trump was the fourth of five children to Fred Trump, a ruthless Queens builder and property developer, and his Scottish-born wife, Mary

However, it later emerged he had exaggerated. The teacher, Charles Walker, remembered Trump as supremely attention-seeking. Told on his deathbed that Trump was running for president, he reportedly remarked that even at ten, Donny had been a ‘little s**t’.

Trump was more successful at sports than he was in class. He adored baseball and, needless to say, played it aggressively. He loved to hit balls directly at the fielders rather than away from them.

A team-mate recalled lending Trump his bat once, only to see him do badly and furiously smash it on concrete, cracking it and not bothering to apologise.

Trump’s home life offers clues to his fierce competitiveness and limited social skills at school.

Moustachioed Trump Sr was a tight-fisted and dour disciplinarian who was determined to toughen up his sons so they could follow him into a life as a ruthless, cost-cutting businessman.

The children were banned from having pets or calling each other nicknames at home, and were urged to earn pocket money by collecting empty bottles for their deposits. Donald and his brothers needed to be ‘killers’ in everything they did, he urged.

Young Donald and his school pal Peter Brant, who became a publishing tycoon, found some freedom by sneaking into Manhattan on Saturday mornings and mooching around the big city.

West Side Story, the musical about warring gangs, was a Broadway hit at the time and the two boys emulated the hoodlums by buying flick knives in a shop where they normally bought stink bombs and fake vomit.

It was Aristotle who said ‘Give me the child until he’s seven and I will show you the man’, and Donald Trump, now 70, would certainly agree

He loved to compete for medals for best-made bed or shiniest shoes, earning a reputation as intensely meticulous, just as his Scottish-born mother had been

Trump hardly seemed that serious a rebel, but when his authoritarian father discovered his knife collection and the secret Saturday trips, he decided drastic action was needed.

In 1959, 13-year-old Donald was packed off to New York Military Academy, a strict Army-style boarding school 70 miles outside the city. Some have speculated that Trump never got over such a harsh banishment by the father he tried so hard to emulate. Off went that hairdo for a crewcut as Trump had to knuckle down to a harsh regime ruled by a drill sergeant who smacked students in the face if they disobeyed him, and punished academic under-achievers by making them box each other.

Offences included unpolished shoes, ‘not walking properly’ and ‘holding hands with a young lady’. Years later, that drill sergeant, Theodore Dobias, recalled how Trump ‘just wanted to be first in everything — and he wanted people to know he was first’.

It was the sort of place where the stocky, athletic and hyper-competitive Trump could thrive, and he did.

He loved to compete for medals for best-made bed or shiniest shoes, earning a reputation as intensely meticulous, just as his Scottish-born mother had been. Boasting loudly of each of his father’s new business successes, he assured other students he would be famous one day.

Promoted steadily up the cadet ranks to become a captain — a sort of senior prefect — he loved wielding his authority, although he was famously soft-spoken.

He once ordered a cadet to be whacked on the backside with a broomstick for performing a drill badly. On inspection duty, he found an unmade bed and hurled the sheets on the floor. Its incensed owner, Ted Levine, recalls hitting Trump with a broom, whereupon furious Donald tried to push him out of a second-floor window before they were separated by other cadets. Trump, Mr Levine recalls, would threaten to ‘break’ anyone who defied him.

‘When I look at myself in first grade and I look at myself now, I’m basically the same,’ Trump told a biographer

As he stands with his finger on the nuclear trigger, as President of the United States, such an observation is more than a little terrifying

He had a lighter side, though, loving to listen to Elvis Presley and Johnny Matthis on his record player. The man now famous for his orange perma-tan would occasionally screw an ultra-violet lightbulb into an overhead socket and tell his room-mate that it was time to get a tan. ‘We’re going to the beach!’ he’d joke.

Trump appalled millions during the presidential election campaign last year when his ugly bragging about groping women was exposed.

Suffice to say it wasn’t the first time he has denigrated them. In his last year at boarding school, he earned a reputation for inviting pretty girls on to campus and ostentatiously showing them around (the boys weren’t allowed out of school grounds).

‘They were beautiful, gorgeous women, dressed straight out of [the smart department store] Saks Fifth Avenue,’ said George White, a former classmate.

Trump wasn’t quite so generous in return, once telling White that one of his own female visitors was a ‘dog’. Even so, Trump was named ‘Ladies’ Man’ in his final school yearbook, posing for a photo with a young woman who was recently identified as a school secretary.

Even in his late teens, Trump —possessing a confidence that convinced other cadets he viewed school as simply a step towards greater things — saw his future mapped out. It was a future following his father into making a fortune as a property developer.

Put in charge of the academy’s drill team for New York City’s Columbus Day parade, Trump — wearing full uniform and white gloves — marched along Fifth Avenue to St Patrick’s Cathedral, where he shook hands with the city’s Catholic cardinals.

However, clearly his mind was on higher things. ‘You know what?’ he whispered to a school mate. ‘I’d really like to own some of this real estate some day.’

Of course, we all know he did. Leaving school, he avoided the Vietnam War draft, not just once but five times, and followed his father into the business.

‘When I look at myself in first grade [aged six] and I look at myself now, I’m basically the same,’ Trump told a biographer.

‘The temperament is not that different.’

From most other adults, such an observation would sound endearing. Now, as he stands with his finger on the nuclear trigger, as President of the United States, it’s more than a little terrifying.