GOOD QUESTIONS: Flipper wasn't just a pretty face

A mixture of new questions and old favourites fill today's selection of instant relief for intellectual angst.

Are dolphins really more intelligent than humans? (M Smith of Rotherham)

There are three sentences to be extremely wary of in any discourse involving the human brain: 'We know how memory works'; 'Of course, we only use 10 per cent of our brains'; and 'Dolphins are more intelligent than humans'. Hearing any of those, we should suspect that the speaker is an expert in what Norman Schwarzkopf calls bovine scatology. For all three are based on old theories of brain functioning that have, at the very least, never been confirmed.

The idea that dolphins were more intelligent than humans has its roots in a 19th-century belief that large brains were better than small ones. The French started it with the autopsy of Baron Georges Cuvier in 1832. The finest doctors in the land pronounced his brain, which weighed in at 1,830g, to be the largest ever recorded. After that, everyone wanted to have a large brain. Ivan Turgenev took the title from Baron Cuvier by 182g, but the sport of brain-weighing soon gave way to estimates of cranial capacity.

By 1910, over 100 eminent men had had their cranial measurements taken, but it soon became clear that there was no correlation between head size and intelligence. When a post mortem on the writer Anatole France revealed one of the smallest brains ever seen, the French finally decided that size was not important.

Interestingly, however, if we compare human brains with ape's brains, either in absolute size or as a ratio of brain-to-body weight, it is clear that we are far better endowed. Compared with gorilla brains, ours are more than twice the size, and our body weight is lighter. It is that sort of measurement that looks good for dolphins, whose brains are bigger than humans' both absolutely and as a percentage of body weight.

Yet the claims for extremely high dolphin intelligence are largely anecdotal, although they are certainly easily trainable, have nice smiles, and are very good at fighting sharks. There are some academic studies suggesting an ability to manipulate sign language and possible high-level conceptual skills, but nothing remarkable (compared, for example, with chimpanzees) in problem-solving.

The connection between brain- size and intelligence remains a very grey area, although a 1974 study did conclude that for humans of similar sex, there was a positive correlation of 0.3. It has been suggested that intelligence may be a function not of brain size, but of the number of neuronal connections, which is a fine conjecture to make, since nobody has any good idea how to make the measurements necessary to test it.

When is Easter on time? It seems to be early or late every year. (Michael Haynes of Crouch End, London)

It is perfectly simple. Easter Day is the first Sunday after the first full moon that occurs on or after 21 March. As Whitaker's Almanac explains, it was so ordained in an Act of Parliament of George II, which points out that the day of the full moon depends on certain tables based on the early pages of the Book of Common Prayer.

'The moon referred to is not the real moon of the heavens, but a hypothetical moon on whose 'full' the date of Easter depends, and the lunations of this 'calendar' moon consist of 29 and 30 days alternately, with certain necessary modifications to make the date of its full agree as nearly as possible with that of the real moon, which is known as the Paschal Full Moon. As at present ordained, Easter falls on one of 35 days (22 March to 25 April).'

In 1928, the House of Commons agreed to the third reading of a bill that would make Easter the first Sunday after the second Saturday in April, but they are still waiting for agreement from the various Christian churches.

Why is 'brumby' the word for a wild horse in Australia? (Vera Brumby, Chatham, Kent).

There are two good and totally unrelated reasons. Partridge's Dictionary of Slang and Unconventional English tells us that the word has been known since around 1864, and appears in Kipling's Plain Tales from the Hills.

He suggests, very plausibly, a connection with the Aborigine word 'booramby', meaning wild. He also mentions, however, an article on wild brumbies that appeared in The Illustrated Tasmanian in 1935, which dates the term back to the 1810s and the appearance in New South Wales of Major William Brumby, of Yorkshire, who was a keen horse breeder who let many of his young horses run wild.

'Brumby' is also Australian slang for a poor hand on which one bluffs at cards.

FEEDBACK:

Following our mention of the origins of the word 'digs' to mean lodgings, we have had a number of letters from readers of Sir Arthur Conan Doyle, pointing out the use of the word on the very occasion on which Sherlock Holmes met Dr Watson. S Parker of Claygate, Esher, provides the full words of Young Stamford, who made the introduction: 'My friend here (Dr Watson) wants to take diggings; and as you were complaining that you could get no one to go halves with you, I thought that I had better bring you together.'

Since A Study in Scarlet, from whence the quotation is taken, was published in 1887, it appears to pre- date our reference to Stage in 1893. However, you have overlooked one important fact which, admittedly, we did not make clear. The reference to the earliest appearance in Stage was to the abbreviated expression 'digs', not the longer form 'diggings'. Stamford was clearly unfamiliar with theatrical idiom.

A reference in our Silly Questions column to brass monkeys and where they go in summer, has led to two enlightening letters, from Saranne Davies of Mergavenny and Christopher Tomlin of Manchester, both telling us what a brass monkey really was.

They both describe it as a brass stand on which ships' cannon-balls were stacked. In very cold weather, the stand contracted sufficiently for the cannon-balls to roll off. Hence 'cold enough to freeze the balls off a brass monkey'. The OED gives some support to this explanation, with a 17th-century meaning of the word 'monkey' as a ship's cannon.

(Photograph omitted)