When a big decision comes along, we generally ask other people for their input – colleagues, family, friends, professionals. People who don’t have a vested interest in the outcome, but who we reckon will be able to give us a balanced, unbiased opinion.

Ah, if only. But there’s no such thing as an unbiased opinion, by definition. Facts may be unbiased (although which facts? I’ll come to that in a minute …) but an opinion is always a personal standpoint, and everyone has their own take.

Suppose you’re thinking of investing in the property market and you know someone who has done the same thing themselves. Ideal! They’ll be able to give you the lowdown, won’t they? Well yes, they will, but only from their perspective. If it worked out well for them, they’re likely to advise you to go ahead. But that’s their personal biased opinion. If it didn’t work out for them, they’ll probably advise you the opposite. And yet you and I both know that some property investments go well and others don’t, so their standpoint isn’t going to be the only one.

I’m not saying don’t consult them. They will probably have some useful insights. But don’t think just because they have more experience than you that their advice is necessarily right. If you can find someone with a different track record, that will help to balance things. However what you have now is two personal opinions from people who have more experience than you. Neither might be right for you. Just remember that.

This brings us back to facts and whether they’re biased. Assuming the facts you collect are true,²⁶ whoever is presenting them will have chosen which facts they consider relevant, and that process contains an inherent bias. You only have to look at how political parties argue over facts to see this process taken to its logical conclusion. Usually (although perhaps not always) both will present true facts that seem to support opposite arguments. That’s because they pick different data, or present it in different ways, so it appears to say what they want it to.

You might be consulting someone who has no intention of doing this, but it’s unavoidable. People have deep-seated and sometimes unconscious beliefs about things that influence their perception of the facts. Imagine asking advice about property investments from someone born into wealth and then from someone who grew up in a council house. They might well have very different values around the ethics of housing, and these are likely to be reflected in their advice. They may not realise it, but they are likely to quote the facts that back up their beliefs (see Rule 92).

Look, I’m not saying you can’t ask anyone’s advice. I’m just saying be aware of this stuff. A Rules player thinks about these things before asking advice and weighs them against the advice itself.