As Fabio Capello weighs up the relative merits of Peter Crouch and Jermain Defoe for his World Cup forward line, it is unlikely he will be taking into account the views of social psychologists. Perhaps he should.

Research on the apparent human tendency to associate size with power and aggression has shown that football referees are notably more likely to penalise taller footballers when they tangle with less lofty opponents, potentially bad news for the 6ft 7in Crouch but a boon for fellow striker Defoe, who is a foot shorter.

A study of more than 100,000 fouls in domestic, European and international football showed that the greater the height difference between the players involved then the more chance the referee will adjudicate in favour of the shorter one.

Academics from Rotterdam school of management in the Netherlands tested the hypothesis further by getting panels of football fans to view mock-up images of two players heading towards a ball equidistant between them.

When asked to speculate which of the pair would be more likely to end up on the ground, and for what reason, there was a clear bias towards assuming the smaller player would be the victim and the taller one the aggressor.

"You will always get moments in a game when the situation isn't very clear and the referee has got to make a fast decision. This is where assumptions could influence them," said Steffen Giessner, one of the co-authors. "There are, of course, lots of causes and effects taking place here. There is an effect with height, but we can't say precisely how strong it is."

Giessner has carried out research into height and perceptions of power in business leadership. This study was partly inspired by an observation by his co-author, Niels van Quaquebeke, that as a keen but relatively short basketball player he got the impression he was rarely penalised for fouls.

Without sufficient data for basketball the pair examined statistics from the German domestic league, Champions League and World Cup, and found that where players were between 6cm and 10cm taller than opponents they were blamed for almost 60% of fouls.

"It's very much about visible height difference. The effect is much stronger the greater the differences in height," said van Quaquebeke.

The researchers speculated that some of this effect might be due to taller players predominating in positions such as defence, where fouls might be more common.

But closer analysis of the data found this was not the case – in fact the greatest number of fouls were carried out by relatively small midfielders against other players in the same position.

The findings are likely to underplay the true situation, the authors say, as the fouls considered included a lot of unambiguous offences where height played no factor. Additionally, the data excludes occasions where fouls by shorter players were missed entirely by referees.

There is, of course, another explanation: that taller players really are more aggressive. The only way to sort that out, the authors suggest, would be to film a series of matches from multiple angles and analyse the refereeing decisions.

In the meantime Giessner, as a German national, has no words of advice for Capello. But he does venture a plan for his own country's football coach, Joachim Loew, when it comes to the combative left back, Philipp Lahm, a modest 5ft 7in.

"You wouldn't call Lahm a dirty player, but he's certainly quite aggressive. And even as a defender he never seems to have many fouls given against him," he said.

"If I was Joachim Loew at the World Cup, I'd be advising Lahm to get into the opposition penalty area as often as he can, fall over and see what happens."