When we find ourselves in need of advice, guidance or even simply information, we commonly seek out familiar confidants. We start with the people we already know and trust. They might be someone we know on a personal level. Or it could be we know them on a professional level or just know of their reputation in a certain area of expertise.

Their credibility in our eyes may be because of their experience or credentials, or from referrals from other people who have credibility with us.

Credentials themselves are an interesting topic. We are trusting strangers whom we believe to have expertise to designate who else has expertise in a certain arena. For instance, we trust universities to vet doctors and engineers, and government agencies to vet insurance agents and general contractors.

So far everything is fine. But where things go off the rails is when we start seeing a targeted expert as a general expert or a trusted friend as a trusted source on all topics. It’s easiest to see when the areas of expertise are far apart. If you doctor gives you advice on auto repair, it may be obvious that this is not his line. But when your doctor gives you advice on nutrition, you may be inclined to assume that he must have this expertise. Alas, most medical schools include very little or perhaps nothing at all in their curricula about nutrition.

I just made a direct statement about doctors and nutrition. Do you believe me? If you do, it is because I have some standing credibility with you. But I am neither a doctor nor a nutritionist. It may be that what I said is accurate. But basing your confidence in my statement on unrelated credibility can get you into trouble.

There is no area where this phenomena is more prevalent (and more damaging) than when it comes to business advice. It seems that everybody will weigh in on any business topic you like. They all have an opinion, often without a shred of pertinent experience. But you listen and you trust. Why? Because they are smart or they are a close friend or they are so confident or they are your beloved uncle Billy Bob.

You don’t have to stop trusting them and of course you don’t have to stop loving them. But do not be sucked into believing they are an expert on all things because of your fond relationship.

Just remember:

• Credibility has limits.

• Credibility has a shelf life.

• Credibility requires context.

Trust your doctor about your prescription. Trust your Gramma about apple pie. Trust your buddy about beer. Just be mindful of the limits of their expertise.

Remember that past expertise may not be expertise any longer. “Back in my day we didn’t worry about drinking what came out of the tap,” says Grampa. I love you, Grampa, but it’s not back in your day anymore.

Just because I’ve “worked with computers” my whole career does not mean I know anything at all about javascript or motherboards or embedded chips. I’m not even sure what some of that stuff was that I just typed. The point is, the context of my computer expertise is critical if you intend to listen to my counsel in those areas.

So stop accepting the advice of credible people who pontificate about topics outside of their expertise. But when uncle Billy Bob is talking football, you better listen and listen good.

Who have you listened to when you shouldn’t have? Tell us about it by commenting below.