The Head and Shoulders Effect

The Head and Shoulders effect. I named this after the 90s TV adverts for the shampoo. Their tagline was “I never knew you had dandruff.” In the adverts, one surprised individual asks their well-coiffed friend why they are using an anti-dandruff shampoo when they clearly don’t have dandruff.

More generally, the question might look like: why are you taking a preventative measure for something I didn’t realise needed preventative measures?

It always struck me as wrong and illogical as a question (but great advertising if you look at their sales results).

Recently, I’ve come across this style of question in real life (adverts don’t count as real life, despite what they want us to believe). I’ve been asked why I was watching what I was eating since I was already slim. The answer is that I’m slim because I watch what I eat (mostly…).

I think the Head and Shoulders effect nicely illustrates confirmation bias: our tendency to interpret information in a way that tends to confirm our beliefs.

There’s a darker angle to confirmation bias. I see this as the flip-side of the Head and Shoulders effect: “I’m taking measures, why aren’t I seeing results.”

I think the answer – and the problem – here is that sometimes we shouldn’t be comparing our progress to where we were at the start of the journey but to where we would be today if we hadn’t chosen to make a change.

For example, it’s very easy for me to feel bad about the slow progress I’ve had trying to improve my running fitness but if I instead think where I would be if I hadn’t done any training at all suddenly it’s obvious what the value is.

I think today’s lesson is to be kind to ourselves by realising that we can’t always directly measure the impact of our efforts because we can’t know what would have happened if we hadn’t tried, and to treat ourselves to a great shampoo.