Human Swarm

22 May 2013

We all like to think of ourselves as individuals, making up our own minds what to do and when to do it.

But this eye-opening new documentary, presented by Jimmy Doherty, reveals new evidence that suggests that in many ways we actually think and move like members of a herd of animals.

We each leave behind us a vast ‘data trail’ every time we travel, use our phone or credit card, search or buy online, use social media or visit a supermarket. That data adds up, making up part of the2.5 billion gigabytes of data – equivalent to 67.5 billion Encyclopedia Britannicas - created across the world every day.

The documentary reveals how, by analysing and unlocking this mountain of data, scientists are able to monitor, predict and even manipulate our actions.

One of the most powerful influences on each of us is the temperature, with the smallest changes affecting us physically and psychologically – without us even being aware of it.

The programme shows how, when the temperature drops, our appetite increases, our mood alters and our health suffers in many surprising – and surprisingly precise - ways.

This March was the coldest in fifty years, leading each of us to demand nearly 20% more gas and electricity than usual to heat our houses. And when63 million of us are doing the same thing at the same time the effects multiply.

In the UK our collectiveCO2 emissions for a year are enough to build a solid tower of carbon weighing 18 million tonnes and over 1,000 feet tall – so big it would dwarf the country’s tallest building, The Shard.

So it’s vital that energy suppliers have accurate weather forecasts to ensure enough electricity and gas is available immediately. The Met Office has one of the most powerful super computers in the world, capable of one hundred trillion calculations per second, which tracks temperature and weather data round the clock, providing detailed forecasts for the whole country, down to less than the nearest mile.

Our swarm behavior continues when we leave our homes. When the temperature drops below 10C we use 43% more fuel just in the first mile of journeys. The cold makes the oil thicker; the engine needs a richer mix of fuel and air; and colder air in the tyres reduces their pressure and causes more friction. Cold weather motoring adds up to an extra £1.4 billion to our annual fuel costs.

We eat differently when it’s cold too. Sales of porridge soar – Pret a Manger sells 44% more porridge and Quaker Oats sell 200% more than normal, 20 million packets each week. Although we all make individual decisions about our breakfast, the overall result is that we act in a very similar way to a swarm.

Our biology is to blame .The hypothalamus is a tiny gland in the centre of the brain acts as a thermostat keeping the body’s core temperature at 37C.To prevent heat loss when its cold the it sends instructions to constrict blood vessels in our bodies’ extremities and it makes us all want to take on more food.

Very small changes in temperature can have a profound effect on our health, as revealed by combining weather data with government statistics, social media and online search terms.

In December 2012, with the temperature regularly below freezing, visits to outpatients clinics shot up by 669,000 compared to the previous quarter. And  analysis of 84,000 hospital admissions reveals that for each drop in the temperature of just one degree there were an additional 200 heart attacks.

The cold contracts our veins and capillary vessels, the blood thickens, making it more likely to clot, which can trigger a heart attack. In a cold winter this individual risk contributes to an extra 75 deaths per day in the UK.

Flu is also more prevalent in winter - nearly 20% of us caught it this winter. It’s because the virus survives longer in cold dry air, while in summer it is killed off by sunlight and heat. Meanwhile sales of Vitamin C rocket by up to 30% in January, even though there’s no hard evidence that it fights colds or flu.

But things may be different in the future. New ways of combining weather information, health data and the internet mean that we can track the outbreak of diseases as they happen. And this could help doctors to stop it in its tracks.

Websites such as sickweather.com scan live social media for phrases associated with being unwell and then match these to the geographical location of the user. Another website, Google Flu, collects data from online searches to map the spread of viruses around the world.

The hope is that in the future health authorities will use this live flow of data to help target immunisation programmes and contain the outbreak of disease.

Many businesses use the Met Office’s weather and temperature forecasts to run their businesses effectively. Combined with their sales figures the results can be extraordinary – when temperature changes dramatically they know what we want to buy even before we do.

At Morrisons’ 1.2 million square foot distribution centre in Yorkshire, the biggest in the UK, the supermarket’s ordering system uses five years’ sales and weather data to predict what we will want to eat and automatically select the right food to its stores.

Over this Easter weekend, the coldest on record, sales of pies were nearly 250% above normal. But, more surprisingly, cat litter sales were 15% higher, because our cats stayed inside. And sales of dishwasher salt went up by 138%, not because we have dirtier dishes, but because we think – completely wrongly – that it will clear our drives.

Meanwhile the winter months see the temperature rise in bedrooms: dating web sites report an increase of 350% in traffic after Christmas and conceptions rise by 5% in the cold winter months.

Likewise, when the temperature rises, we can be equally predictable.

With three days of warmer weather, and the mercury hitting a ‘magic’ 18C, stores know we will all decide, quite independently, to have a BBQ. Within minutes of receiving a forecast of good weather, Morrisons divert from producing beef mince for casseroles to make burgers - distributing up to 1.2 million burgers per week, as well as the accompanying salad, buns and beer.

The programme also shows how weather affects other retailers. Debenhams report a 50% rise in sales of swimwear in January as people book summer holidays (bookings on Virgin Holiday’s site go up 40% in the same month). Bravissimo reports a staggering 600% increase in sales of swimwear if the sun shines, whatever the time of year or temperature, and their online advertising automatically changes when the weather forecast does.

On weekend of April 20th this year, when the temperature reached 18C for the first time in 2013, online search for DIY items rose by 50% from the previous day and searches for mountain bikes doubled. There was also a 50% increases for the word ‘pub’ and a 54% rise in searches for tanning salons.

“We are at the dawn of a data revolution - the amount we produce in our daily lives is increasing,” says Jimmy Doherty. “I can totally understand why this can all seem a bit disturbing – that everything we do is now stored as data - but when all this information is matched with the weather data it really does increase our understanding of our behaviour – as a human swarm.”