MANCHESTER United, Ferrari, Tiger Woods and Spain all have one thing in common which may explain their overwhelming success.

New research by North-East psychologists has found evidence to show that putting on a red shirt can give individuals and teams a physical and psychological advantage.

Interestingly, Cardiff City Football Club were promoted to the Premier League this season after changing their strip this season from blue to red.

Previous research has shown that wearing red can be an advantage in competition, either by inhibiting opponents or by giving the wearers of red a form of mental advantage.

Now new research from Sunderland University, published in "Psychological Science" has shown for the first time that an individual's testosterone levels are associated with the choice of colours they make when taking part in competition.

In this study, which involved 73 men, it was found that males who chose to wear red in a competitive task had higher testosterone levels than other males who chose to be blue. Dr Daniel Farrelly, a senior lecturer in psychology at Sunderland University, believes this may explain why teams as well as individual sports stars in red could be much more successful than those wearing other colours. Dr Farrelly said: "This study reveals that there may be something intrinsically different about 'red' competitors, that can give them an advantage."