I was walking down a local road recently and I could see ahead of me a speeding warning sign. The sign flashes the maximum speed that you should be travelling for any vehicles exceeding that speed limit. For this sign that speed is 30 miles an hour since it’s a residential area.

The sad thing was, as I walked along the road on a busy weekday evening, every vehicle that passed me received the flashing warning sign that they were exceeding the speed limit. Not only that, but I looked at the break light panel of all the vehicles that passed and none of them applied their brakes. Put simply, they all ignored the ‘request’ of the sign.

Human nature being what it is, however, generally doesn’t respond well to what it’s told it’s doing wrong. “30” was the flash and it had zero impact on the slowing down of the drivers. Something tells me too that there may well have been a handful of drivers who reacted by driving faster. What I also do know as fact is that there is now a speed monitor across the road further up the road.

In another village not to far from me there’s another driver sign. Whenever you travel no faster than the maximum speed limit it flashes “Thank you”. Whenever I’ve driven there I’ve noticed some drivers slow down. Not all but that will always be the way for some simply won’t respond positively. Some drivers do slow down though.

It seems to me that flashing “Thank you” in someone’s face to doing what you want them to do brings a better response than flashing “30” in their face for doing what you don’t want them to do.

The moral of this anecdote. I’ll let you decide.


Does your teenage child’s behaviour seem irrational or just plain weird to you? If so, science might offer an explanation as to why your child’s cavalier approach to life seems so natural to them – and so irresponsible to you.

This is not an excuse, mind. Just because there might be an explanation doesn’t mean it’s acceptable. It’s merely understandable and there is a world of difference between the two.

So, whats going on?

The Psychological Journal posted the conclusions by Roper, Z. et al in June, 2014, the title of which was called Value Driven Attention Capture in Adolescence. The scientists lead by Vaidya, J. G. trained both adolescents and adults to engage in a computer ‘spot the object and receive a reward’ program, hence the title of the research: Value Driven Capture.

The research showed that both adults and adolescents responded well to receiving a reward so no surprise there. Both age groups were then given a different target to identify. What might be surprising was the residual effect of the previous task on the two age groups. Whereas the adults’ reward mechanism for the initial target quietened allowing them to more easily adapt to the new target, the adolescents’ reward mechanism for the original target remained high and they experienced considerable difficulty adapting. It was as if the original reward desire was still firmly in their mind.

There are implications here for adolescents suffering from ADHD since the lack of self-control often experienced by people with ADHD might be tied in with their lack of reward system adaptability. The research may also offer insights into why teenagers can persist with something when to the rest of us it’s over or just no point pursuing. For example, a teenager laughing at something, the situation ending, but the teenager still ‘goes on and on’ about it. Or, what about teenagers’ love of texting and social media? It’s a ‘moth to a flame’, as the value driven reward is sought over and over again when adults would have let go and moved on ages ago.

It seems that the very means by which teenagers process rewards may be the key to their extraordinary behaviour and not the previously thought cause being the under-developed frontal lobes of the brain that are responsible for self-control.

So, listen out for: “Sorry, mum. My irrational behaviour is as a result of a value driven attention condition and not, as previously thought, because of my under-developed frontal lobes in my brain. Can I have some more money to top up my phone?”