In 1955, Peter Drucker, the management guru, wrote in The Practice of Management: “The constant worry of all personnel administrators is their inability to prove that they are making a contribution to the enterprise. Their preoccupation is with the search for a gimmick that will impress their management associates. Their persistent complaint is that they lack ­status.”

Fifty years on, and they tend to travel under the name of “human resource” managers. But while much has changed about the human resources they purport to manage, the stereotypes that surround HR are a source of stability in the changing world of work.