There has been considerable debate about the safety of WIFI signals of late.

Reading your paper it appears there are two groups, the first finds then WIFI signals make them ill and damages their quality of life. The second feels that there is no scientific evidence of any way WIFI signals can affect people and that the first group are being at best oversensitive.

I believe that there is a relatively straightforward explanation of this apparent paradox.

In medicine the placebo effect is well known and studied extensively. If you give someone a treatment, patients can feel better even if there is no active drug it, this is not just a mental effect. For example, blood pressure will measure lower in some patients given ‘blood pressure medicine’ even though the tablets they take are just dummies.

There is an opposite of the placebo effect, which is less well known; it is the nocebo effect. For example, a patient taking a medicine that they believe has a side effect of headaches may get headaches even if the treatment has no active ingredients. To clarify this, from their point of view, they have a headache. They are not imagining they have a headache or making up a story about them having a headache.

I suspect that sensitivity to WIFI may have a similar aetiology. People believe that WIFI will harm them, and so it does. The effects they suffer are real; it is just that the WIFI itself doesn’t cause them directly. So we shouldn’t disregard their problems however neither should we discard WIFI as a terrible threat to most people’s health.

Further indirect evidence that this is the case is that there are a large number of products that people can buy to help them with their problem. There is no scientific evidence that these should work; however, many people buy them and find they help. They are combating a nocebo effect with a placebo effect. I think that’s a perfectly pragmatic approach.

In short, I believe that people with sensitivity to WIFI and the debilitating effects it can cause deserve support. However, they need to realise that their problem is related to them and their response to their environment, not to some awful thing that can damage everyone.

I fully appreciate that this letter may serve to unite both groups in disagreeing with my views.

Yours faithfully

Steven Tilley

Cambridge