A sheep is more intelligent than a dog?

Well, researchers at Southampton University, in a study made on 8,179 subjects, found that intelligent children are more likely to become vegetarians later in life, by the age of 30. The vegetarians recorded five IQ points more on average at the age of 10.

Most people chose a vegetarian diet as healthier, linked to lower heart disease and obesity rates. Twenty years after the IQ tests were carried out in 1970, 366 of the participants said they were vegetarian - although more than 100 reported eating either fish or chicken.

Vegetarian men had an IQ score of 106, compared to 101 for non-vegetarians; while vegetarian women averaged 104, compared to 99 for non-vegetarians. No difference in IQ score was found between strict vegetarians and those who said they had a vegetarian diet supplemented with fish or chicken.

Researchers said the findings were partly related to a better education and higher occupational social class, but it remained statistically significant after adjusting to these factors.

Most vegetarians were female, of higher occupational social class and with higher academic or vocational qualifications than non-vegetarians.

However, these differences were not reflected in their annual income, which was similar to that of non-vegetarians. "The finding that children with greater intelligence are more likely to report being vegetarian as adults, together with the evidence on the potential benefits of a vegetarian diet on heart health, may help to explain why higher IQ in childhood or adolescence is linked with a reduced risk of coronary heart disease in adult life." said Catharine Gale, lead researcher.

"The link may be merely an example of many other lifestyle preferences that might be expected to vary with intelligence, such as choice of newspaper, but which may or may not have implications for health."

Liz O'Neill, of the Vegetarian Society, said: "We've always known that vegetarianism is an intelligent, compassionate choice benefiting animals, people and the environment."

"Now we've got the scientific evidence to prove it. Maybe that explains why many meat-reducers are keen to call themselves vegetarians when even they must know that vegetarians don't eat chicken, turkey or fish."

"It is like the chicken and the egg. Do people become vegetarian because they have a very high IQ or is it just that they tend to be more aware of health issues?" said Dr Frankie Phillips, of the British Dietetic Association.