Horses have the same ability to count as human infants, a study has shown. In tests the animals watched plastic apples being placed out of sight in buckets and then chose the one containing the larger number.

Using fake apples ensured they were not relying on their sense of smell to make the selection.

Scientists said the horses showed they could keep a tally of how many apples were going into the containers and hold the thought in their heads before deciding which bucket to investigate.

Their behaviour mirrored that seen in similar experiments involving human babies and wild rhesus macaque monkeys. The research was conducted by Claudia Uller and Jennifer Lewis from the University of Essex.

Binge drinking can permanently damage the short term memory of teenagers, according to the most up-to-date research on alcohol abuse.

The memories of 17 to 19-year olds who drink at least eight units (six for girls) at one sitting at least twice a week was measured in a series of controlled experiments.

The binge drinkers could remember up to one third less of the 18 instructions they were told to follow during a shopping trip three days after they had last had a drink, compared with those who drink only moderately or not at all.

The instructions included simple actions such as: “Go to Boots and buy and toothbrush” and “Text a friend when you arrive at WH Smiths”.

The research was conducted by the University of Northumberland. Dr Thomas Heffernan, senior lecturer at the university and one of the authors, said the developing literature on how alcohol affected teenagers suggested the effects were swift because heavy drinking damaged parts of the brain that were still developing.

Married couples are just as unhappy as they were when they were single four years after the wedding, according to a Nobel Prize-winning scientist.

Professor Daniel Kahneman, one of the world’s leading experts on happiness, blamed couples’ inflated expectations of marriage which invariable led to feelings of disappointment.

They had to accept marriage was a ‘trade off’ with a price to pay for the constant companionship and availability of sex. The price was more time spent doing things they do not like doing, such as housework.

Drawing on life satisfaction data from a huge ongoing study in Germany, he said contentedness peaks at the time of the wedding but quickly falls off. After four years, the respondents reported the same level of satisfaction as they did when they were single.

“Marriage is a balance of costs and benefits in terms of time. They get more sex and they are less alone, but they pay for with other costs they don’t necessarily enjoy it in terms of time,” he said.

On-line role-playing games take over the lives of one in thirty users who become totally addicted to playing, according to new research.

The addicts cut back on sleep, miss meals, neglect their jobs and often destroy relationships with friends and family in order to keep playing, the study found.

Millions of people log into multiplayer role playing games. World of Warcraft, the best known, has over eight million regular players alone and there are dozens of others with over a million members.

Academics from Whitman College, Washington, and the University of Bolton, examined in close detail the behaviour of 400 regular players of another game entitled Asheron’s Call drawn from around the world.

They drew up four criteria specially to measure online gaming addiction to try and weed out those who were just ‘heavily engaged’.

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