by MERLIN CROSSLEY

 These days stories “go viral” on the internet, but even in the old days short fables spread widely through the community. I remember very clearly, I was about 25, when a friend of mine in the lab in Boston explained to me the Streetlight Effect or Drunkard’s Search. I wonder when each of you first heard it, or if you are young, you may not have come across it yet.

The story describes a drunk who has lost his car keys and is searching systematically beneath the only streetlight. Along comes a kindly policeman who joins him in the search. After a while the policeman asks an important question – “are you sure you lost your keys here,” to which the drunk man replies “No, I didn’t lose them here. I lost them over there when I was crossing the park.” “So why,” the policeman asks “are you looking here under the streetlamp?” To which the drunk replies, “because this is the only place where there is enough light to search.”

To me and other junior researchers the message was striking – beware of concentrating just on the techniques you know, of staying within your “comfort zone,” keep in mind the fact that the real answers to your problem may reside elsewhere. So, push yourself to answer the question rather than repeatedly scouring your own territory with your favourite techniques in the hope of discovering something important.

Only years later did I recognise some obvious problems with this fable.

First of all, why did the person who had lost their keys have to be drunk? It paints them in a bad way to start with. Especially, when there are contrasted with a friendly policeman. Secondly, the story is about re-locating something that is lost. During the Renaissance research may well have been about rediscovering lost knowledge but in modern molecular biology the focus is squarely on new discovery. Modern science is seldom if ever about rediscovering lost knowledge. While it sounds sort of stupid to be looking where you can see, rather than where you think the answer lies, sticking to a lighted area makes perfect sense if you are exploring the unknown.

Peter Medawar, who shared the Nobel Prize with Frank Macfarlane Burnet in 1960, probably said it best. “Science is the art of the soluble” and “good scientists study the most important problems they think they can solve. It is, after all, their professional business to solve problems not to grapple with them.”

It makes great sense to search where you have a chance of finding something. You won’t necessarily find your car keys but if you are logical and persistent you will find something because there is so much more to discover. To stretch the metaphor, it is likely the drunk man will find something useful, perhaps a torch, that will allow him to go and look in the park.

By steadfastly working on bacteria, for instance, molecular biologists, have time and time again discovered new tools for manipulating DNA. Back in the 1970s bacteriologists identified the machinery involved in replicating and cutting and pasting DNA and it started the field of recombinant DNA technology. Most researchers now work on humans, or model organisms, like mice, but happily a few researchers kept working on bacteria and it was those people who discovered the machines that enable CRISPR-gene editing.

In these days of translational research I can understand why the public might want researchers to get away from the streetlamp and into the park where the keys were lost – I can see why people with family members suffering from Alzheimer’s Disease may want research on Alzheimer’s, while those suffering from COVID may want researchers to prioritise COVID – and these days it is possible to shine the torch of modern molecular biology on these problems. But we should also remember that the real answers may not come from translational research efforts – CRISPR didn’t come from translation and the COVID vaccines arrived via fairly fundamental work on RNA.

It’s important, sometimes, to let some experts, not drunkards, keep searching under their lampposts. It’s always a balance. We don’t want a professor of steam trains insisting that the low hanging fruit has not yet all been found and that he has an idea for a longer train, but we do need to recognise that in most fields we know so little that spending a bit more time mining out the deep shafts that have been the most fruitful can still be justified.

Professor Merlin Crossley

Deputy Vice-Chancellor Academic and Student Life

UNSW SYDNEY