They carried out an investigation into referees behaviour when it comes to making decisions in the top four professional leagues in the country.
The study - 'No crowds, no home advantage in football during the COVID-19 season: Are crowds able to manipulate all but the best referees behaviour?' has been published in the Journal of Global Sport Management.
The research was carried out by project lead Alan Nevill from the University of Wolverhampton and experts Dr Tom Webb and Alastair Pearson at the University of Portsmouth and compared the number of home and away red and yellow cards awarded in the ‘no crowd’ COVID-19 2020-21 season with ones awarded during the previous ten ‘crowd’ seasons from 2010-11 to 2019-20.
It confirmed without crowds, there was no home advantage in football during the 2020-21 season.
In contrast, referees awarded significantly more cards to away players when officiating with crowds present during seasons 2010-11 to 2019-20.
It also found in more recent ‘crowd’ seasons, Premier League referees were less susceptible to such influences, with a narrowing of the gap between home and away yellow cards, suggesting their preparation, management, and training provide them with an element of ‘crowd immunity.’
The research team’s findings concluded that home crowds are able to influence all but the very best referees’ behaviour.
The findings have the potential to influence the training and development of referees at many levels of the game and to provide referee educators with the information to focus future training initiatives aimed at reducing home advantage further in all professional leagues in England.
Mr Nevill said: “Our study provides overwhelming evidence that crowds are able to manipulate professional referees to award significantly more red and yellow cards to away players compared to home ones an effect that disappears when crowds are absent.”
Doctor Webb said: “Our findings provide powerful evidence that home crowds can manipulate all but the very best referees to be their twelfth man.
“It is interesting that Premier League referees appear to be less susceptible than less experienced referees in lower divisions - there are a variety of reasons why that may be.
"For example, in the Premier League psychologists have been introduced to work with referees and technological innovations, such as goal-line technology and video assistant referees have been introduced to assist referees in their performance.
“Also, the growth of the Premier League has led to increased investment in professional referees and the potential for a wider gap to emerge between these referees and those referees operating within the professional game in the lower leagues.”
Mister Pearson added: “It’s clear that there needs to be more advanced and effective training provision for referees that operate outside the Premier League, such as shutting out the crowds and dealing with hostile environment.
“Further financial investment is crucial to ensure referees continue to develop their decision-making skills.