Trust is vital to getting the most out of relationships with staff and customers, Ruby Wax told delegates at ITT.

The US comedian now runs management courses for companies such as eBay after completing an MSc in psychotherapy and a course in neuroscience.

“If you’re settled and calm, it passes like a virus to your staff and customers,” she said.

Wax talked about the way she built up trust with stars such as Imelda Marcos for television interviews.

“My job was to make people feel so comfortable that they didn’t mind when I took the piss out of them,” she said.

“Trust is making everyone in your office feel human. It’s not about the big sale or the big smile because people can smell a phony.”

She advised delegates to look for common ground when meeting a new customer and be “present” in the conversation.

“Don’t think about things you have to do or what you’re having for lunch, or you won’t be present,” she said.