Why do we knock on wood? We’ve been leafing through the history books to trace the roots of this belief

Don’t want to lose this good thing – as the song goes – well, you better knock, knock on wood. We’ve been using the phrase since at least the 19th century to protect our good fortune but theories as to why link it back even further. It’s thought that in pagan cultures, it was used either to call on the protection of spirits, or scare away malignant forces.

A Christian interpretation links it to the wood of Christ’s cross – as well as a Jewish one, recalling the coded knocks of escape networks during the Spanish inquisition. A later interpretation links to a child’s game of tag, and the knocking on wood that means “safe”, made more plausible by the fact the first written reference to touching wood is as recent as 1899. Nevertheless, variations of the superstition appear in many different cultures. Italians, for example, instead will find themselves “touching iron”.