It is no secret that politicians often lie, but consider this ­– they can do so simply by telling the truth. Confused?

That statement becomes clearer when you realise that we've probably all done it. A classic example might be if your mum asks if you've finished your homework and you respond: "I've written an essay on Tennessee Williams for my English class." This may be true, but it doesn't actually answer the question about whether your homework was done. That essay could have been written long ago and you have misled your poor mother with a truthful statement. You might not have even started your homework yet.

Misleading by "telling the truth" is so pervasive in daily life that a new term has recently been employed by psychologists to describe it: paltering. That it is so widespread in society now gives us more insight into the grey area between truth and lies, and perhaps even why we lie at all.