In recent months, the same headlines seem to keep cropping up in our newsfeeds. The reasons why are simple.

It would appear we cannot go for more than a few days in 2016 before there is another high-profile celebrity death or mass shooting reported somewhere. More recently, in the space of a fortnight Harambe the gorilla was killed for putting the life of a toddler in danger and an American alligator killed a two-year-old in Florida. And in the UK in little more than a week, the prime minister, leader of Ukip, England football team manager, the host of the BBC’s Top Gear and 63 key Labour figures all resigned.

But seemingly coincidental headlines, or spates of disasters are more likely to reflect how we consume news and save memories.

“The sceptic’s response is that a coincidence is bound to happen if you have a sample large enough,” says Bernard Beitman, visiting professor at the University of Virginia and author of the book Connecting with Coincidence. “If you toss a coin 1,000 times, through chance the odds are that you’ll have a run of seven or eight consecutive heads. However, if you tried to toss eight consecutive heads it’s incredibly unlikely. But, because in the first example your dealing with a large sample, it’s not surprising that something seemingly unlikely happened.

“This is a random clustering effect of events. For example, with aircraft accidents, there are probably dozens each year, and eventually you’ll have four or five that all happen in the same week purely by random clustering. It doesn’t necessarily mean that week was much more dangerous for global air travel, though.”

Apparent spates of disasters, like aircraft accidents, are more likely the result of random clustering

“A sceptical statistician will say ‘in a large population, any strange thing could happen’, and dismiss the coincidence as random.”

However, there’s a problem with using the word random. “The statistical definition of random would be that two events are entirely unconnected,” he adds. “But in reality, it’s almost impossible to prove that two events are unconnected, particularly when we’re aware of so much of the discourse in the media. A random universe is hard to prove.”

Consider reports of apparently simultaneous discoveries.

Alexander Bell and Elisha Gray, for example, both had their lawyers file patents for the telephone in different offices on the same day – February 14, 1876. Both designs, and prototypes tested contained many similarities, and some key differences.

However, this isn’t such a massive coincidence. Their work was based on research being carried out by themselves and many other scientists experimenting with the exciting new field of telephonography. The inventions didn’t magically appear out of thin air on exactly the same day, they were an end goal that was being worked towards, and in the end it was a race to finish the designs first to prove you had a working design. It’s not surprising, then, that two researchers both trying to design an instrument for transmitting and receiving vocal sounds filed their patents at the same time.

In 2016 there were a ‘phenomenal’ number of high-profile deaths reported

Even the apparent increase in the number of celebrity deaths reported this year can be explained in a similar way. According to the BBC’s obituary editor, Nick Serpell, in the first three months of 2016 there were a ‘phenomenal’ number of high-profile deaths reported, from David Bowie to Prince, compared to previous years. Between 1 January and 31 March , 24 obituaries were published, compared to five in the same period in 2012.

Serpell suggests there are a few reasons why this might be the case: firstly, a rise in populations 50 years ago means that there are more people dying. “People who started becoming famous in the 1960s are now entering their 70s and are starting to die,” he told BBC News.

“There are also more famous people than there used to be,” he adds, as technology has brought more public figures into our living rooms. “In my father or grandfather’s generation, the only famous people really were from cinema – there was no television.”

Similar reasoning may explain a bizarre coincidence in the history of comics. In 1951, two new series of comic strips – one British, one American – were published for the first time. Both featured a young boy, his dog and the mischief the two got up to – both were called Dennis the Menace. The two comic strips are entirely unrelated, but were so similar they had to be renamed when distributed in each others’ countries to avoid confusion.

The chances of two cartoons with the same name and the same concept being published within five days of each other on different sides of the Atlantic seems highly unlikely, but as Beitman explains, such a coincidence reveals much about the zeitgeist.

A demand for a certain type of story means news editors will look out for similar stories

“There are ideas in the air,” he adds. “Even though these two cartoons were published entirely separately, the creators were probably drawing on ideas that were circulating in the population. It’s the same with news events, similarities between seemingly unrelated events crop up because we’re aware of current zeitgeists.”

This is then reinforced by news editors who see a demand for a certain type of story, whether it’s about celebrity deaths or animal attacks, and so are more likely to cover similar events – however loosely related – to play up to the zeitgeist, because they know that this is what people are talking about.

We’re also more likely to remember remarkable coincidences, explains Beitman. We think that bad news comes in threes, but in reality, pairs of news events are far more likely to occur, it’s just we remember when it comes in threes because it’s more unusual. It reflects a bias in the way we store memories – unusual events stand out to us more.

So if it seems like it never rains but it pours with depressing headlines, that may say more about your own temperament than the state of the world.