Are there any cultures which are predominantly left-handed?

No. Handedness is innate, derived from differences between the left and right brain hemispheres. There is some variation in the proportion of individuals in a population that are left-handed, but it is never more than 20 per cent and usually nearer to 10 per cent, so it would be illogical to base the cultural bias on such a small percentage.
— Gabrielle Shepstone, St Albans, Herts

It is thought that left-handedness, sinistrality, is caused by a sudden secretion of growth hormone in the uterus, which accelerates the growth of the right side of the brain relative to the left side, the right side controlling the left-hand side of the body via the “crossover” pyramidal tracts in the mid-brain. It is unlikely that this endocrinological phenomenon would be modified by cultural factors; indeed, research has shown that the incidence of sinistrality is evenly spread among ethnic and racial types.
— Robert Randell, London SE26

Not in humans, where we will always be a blessed, chosen minority who deign to walk among the prosaic righties. Remarkably, however, left-pawedness predominates for polar bears — who almost always kill their prey with a sinister blow from the superior side.
— Ralph Lloyd-Jones, Nottingham

In order to have a balanced number of cars at each petrol pump, do car manufacturers have an agreement as to which side they fit the fuel tank?

Your correspondent John Moore (Questions Answered, March 14) is mistaken in claiming that Japanese and traditional British cars have fuel fillers on the left.

I have a Japanese Mitsubishi FTO with the filler on the right. I also have a British MGB roadster (what could be more British than that?) with the filler offset to the right on the rear panel.

Many cars now have locking flaps over the filler with a release lever adjacent to the driver. Mechanically, it is easier to connect the lever to the flap if the filler is on the same side as the driver.

— Gerry Howard, Watton at Stone, Herts

What would happen if Britain stopped all imports? What population could we support?

If imports were stopped, the sustainable level of population would depend on success in switching exports to the domestic market and on the level of consumption accepted by or forced on the populace by government controls. A pointer to possibilities was provided in the Second World War when population was sustained by strict rationing, which limited consumption to less than half the prewar level. It was said at the time that people were healthier than they had been before the war because of the balanced diet limited to the minimum daily calorie requirements which rationing enforced. In today’s conditions of widespread obesity, binge drinking, general dietary over-indulgence and levels of consumption, it might be said that “welfare” in its broadest, most meaningful sense would be enhanced if disposable incomes and consumer spending were severely restricted.
— Ray Long, London SW16

Why are ships’ propellers at the back pushing whereas aeroplanes have the propeller at the front pulling?

There have been several designs of aircraft utilising pusher propellers. One of the most impressive was the Convair B-36 bomber, which had six 28-cylinder air-cooled radial piston engines, each with a pusher propeller, mounted on the rear of the wings. It also had four gas turbine (jet) engines. I don’t think it was a great success and didn’t last very long with the USAF.
— Nicholas Dodson Coleman, Newton-le-Willows, Lancs

Are there any U-boats (either operative or otherwise) still in existence? If so, where are they?
— Derrick F. Mant, Basingstoke, Hants

Would wine drunk by the Romans and Ancient Egyptians taste or differ from wine we drink today? If so, how?
— Martin Winter, Royston, Herts

Why is the centre of a shooting target and a dartboard known as a bullseye, while the centre of an archery target is known as a gold?
— C. W. Oliver, Gravesend, Kent

In the days of sail, drowned sailors went to “Davy Jones’s locker”. How did this Son of Neptune get his name, and why was he apparently, a Welshman?
— John Pope, Tisbury, Wilts

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