When I was young the margins of my school books swarmed with doodles of all kinds, a way to practice drawing at the same time as spicing up a maths lesson.

The doodling became habitual: if there was a pen and paper nearby, little pictures sprouted.

The pictures were entirely predictable. I would start by drawing a disembodied eye, then a disembodied mouth. Finally a face – usually female – but not at all connected to the eye or the mouth. The features were just to get my hand in, so to speak.

Then I might branch out into an elaborate, many-petaled flower, a faceted star, or flames emanating from a kind of Turkish lamp, and finally a horse’s head, complete with flowing mane. So far, so girlish.

Given my own preoccupation, I always noticed when someone else was a doodler. But it was the differences in the pictures that were really fascinating.

Hard, straight, geometric shapes or three dimensional boxes couldn’t have seemed more alien. Chequerboard and zigzag patterns, arrows and even signatures just never fell out of my pen, but it seems they are the most common squiggles of those of us who do the doodling.

Apparently, there’s some ‘science’ (armchair, presumably) behind this. Doodles don’t come out of thin air. What we draw has a connection with who we are and the preoccupations of our subconscious.

Curvy, flowing shapes indicate emotional people who want harmony. Practical types might use straight lines and squares. Determined people may use corners, zigzags and triangles, while more hesitant types use light, sketchy strokes.

And faces – well, I don’t come out of this analysis covered in glory. Drawing faces means I’m essentially drawing myself – how narcissistic – and obsessive drawings of eyes and mouths are associated with, erm, more sensuous concerns.

Whatever. The truth is, doodling will probably disappear as we all replace pen and paper with keyboard and smart phone. We’ll have to find other ways to reveal our subconscious hopes and fears.