Portugal's victory over England last night could have been predicted, according to North-East academics.

By beating England on home territory Portugal illustrated a scientifically proven phenomenon.

Two years ago researchers at Northumbria University in Newcastle proved that there was a scientific basis for the well known home advantage in football.

Scientists studying a North-East Unibond League side found levels of the male hormone testosterone were higher in players facing a home game.

Testosterone is association with aggression, confidence and dominance.

Even higher testosterone levels showed up in players from a Premiership junior team about to play at home against their deadly North-East rivals.

The study suggests that humans, like animals, will fiercely defend home territory.

Dr Sandy Wolfson, a sports psychologist who carried out the research with biological psychologist Dr Nick Neave, said: "There is no doubt that there is a very strong advantage for the team playing at home. Even the very worst teams tend to do better on their own territory."

But this did not always result in a home victory, she added.

"If one team is much more highly skilled than another team then that could overcome the home advantage," she added.

Dr Wolfson is continuing her research into testosterone levels in footballers but this year she has extended her studies into female soccer players.

"We are doing some work with some of the top English lady footballers," she added.

She has also worked on research which shows the psychological benefits of being a football fan.

Fans often find it easier to relate to other people if they have the language of football in common.