Why did RAF fighters in WWII have a Spade control stick over a typical pistol grip?

The British fighters, such as the Hurricane and Spitfire had brakes operated with a lever, like a bicycle brake, mounted on the stick. The spade control makes it easy to use.

These aircraft also have their undercarriage controls, (rather quaintly labelled as The Chassis"), on the opposite side of the cockpit from the throttles, meaning that you have to change hands on the stick to get the wheels up after take-off. That is actually a bit of a physical process, you have to hold the lever in the down position for a few seconds, to release the downlocks, before you can bring the lever forward to raise the wheels. It is much easier to do that if you have a grip that fits your left hand as well as your right.

The control column is very different from that on, say, a P51. The cockpits on Spitfires are quite cramped, so you don t have room for the controls to move sideways in a big arc, so only about the top half of the column pivots to move the ailerons, from a point just above the pilot s knee level.

The spade grip is very comfortable to fly with.

You needed two hands on the stick at times.

Different groups of people are accustomed to certain shapes. Germans were use to throwing sticks so their grenades were a stick with an explosive on it. Americans were use to throwing baseballs so their grenades were roundish and thrown like a base ball. American pilots were very accustom to pistol grips due to their culture with guns, including firing the guns on the plane with a index trigger pull. The British on the other hand were not but they were practical. You can grasp the spade control stick with either hand, upside down, sideways, in the middle, etc. It was a lot better if the pilot was wounded as he could work the stick with either arm easily and in a number of ways.

The ring grip at the top of the stick has some ergonomic advantages - You can grip it palm up, palm down, or in between, and with either hand or both if need be. The Brits used it in combat aircraft in WWI through WWII and into the jet age...and some Russian WWII fighters used them also.

Maybe the Brits were more comfortable with holding shovel handles than pistols.