I’ve just read an article about some interesting studies from the clever people at the Influence At Work research group. They highlight how much more effective it is to get someone else to ‘toot your horn’ than do it yourself.

OK, we know that already: the principle has always been at the heart of public relations.

It’s why editorial articles written by an independent journalist can be so much more powerful than advertising, where you’ve paid to talk yourself up. And it’s why we pay attention to online customer reviews of stuff we need to buy and restaurants we want to go to.

But it’s interesting to read about studies that scientifically test the difference this can make.

The Influence At Work team summarises a research exercise, led by Stanford University Professor Jeffrey Pfeffer, where participants played the role of book publishers evaluating an author.

Half of the ‘publishers’ read about the author’s accomplishments described by his agent. The others read the same comments from the author himself.

Strikingly, they rated the author more favourably on almost every factor, especially likeability, when his agent sang his praises – even though the agent was clearly biased, with a big financial interest in the author’s success.

In another study, the Influence At Work team measured the impact of an estate agent’s receptionist presenting the sales staff’s credentials before putting through calls.

She said things like: “I’m going to put you through to Peter. He’s our Head of Sales and has 20 years’ experience selling properties in this area.”

The receptionist was hardly impartial. But the impact of this recommendation was dramatic: a 19.6% increase in appointments and 16% rise in signed contracts.

Why would this work?

Part of the answer must be trust: we give more weight to a third party recommendation than a self-endorsement. But it’s interesting that this seems to remain so even when the third party is clearly biased.

I suspect the other part of the answer is revealed by the inclusion of ‘likeability’ in the Pfeffer study. We simply don’t like people who blow their own trumpets too much.

In the real world, however, it’s not always practical to have someone speak for you: in many situations (e.g. business pitches, job interviews), we have to present our own credentials.

In such cases, people too often seem to feel they have to sell themselves hard from the word go. But no-one likes a smart arse. And people hire people they feel they’d like to work with.

How, then, do you sell yourself without making people hate you?

Influence At Work suggest that one good – if counter-intuitive – solution is to be up-front in confessing minor failures and weaknesses.

This can break down barriers. It can make people warm to you – and believe in you all the more when you go on to talk about your strengths.

This is something I occasionally do and I really think it does help to build trust and empathy. Human nature means you sometimes even get people leaping to your defence.

Third party endorsements and admission of small weaknesses, then, can be powerful methods to help you win people over and build credibility.

How could you harness these techniques in your communications, sales or marketing?