Can economics help us work out the perfect amount to spend on a wedding gift? Economist Maria Kozlovskaya has advice on the factors we need to consider.

Also, when Hillary Clinton almost collapsed at a 9/11 memorial, conspiracy theorists went into overdrive, falsely claiming the presidential candidate was using a body double to avoid questions about her health. The lookalike in question tells her side of the story.

And why do some games, hobbies and activities – like Pokemon Go - become crazes while others do not? Is there a secret formula?

(Photo: Several gifts wrapped and on a table. Credit: Jayme Burrows/Shutterstock)

How many people have died in the Philippines since the Government encouraged the police to clampdown on the illegal drug trade? The new President, Rodrigo Duterte, went as far as saying that citizens could shoot and kill drug dealers who resisted arrest. The press have reported that many thousands are the victims of extra-judicial killings but exactly how high is the death toll likely to be?

Sightings of suspicious clowns have left a US community in fear. Is the town the victim of a viral elaborate prank, or witnessing an outbreak of mass hysteria?

And why do we find certain types of voices or accents annoying ? Does that irritation reveal more about the speaker or about our own biases and prejudices and are irritating voices the same the world over?

(Photo: A Filipino human rights advocate holds a placard as he joins a demonstration in front of the Philippine National Police (PNP) headquarters, protesting the number of deaths related to government's war against illegal drugs. Credit: European Photopress Agency)

World Records are being set at a much faster rate in swimming than in other sports. At the Rio Olympics, British swimmer Adam Peaty managed to break the men's 100m breaststroke world record twice in two days. Tim Harford speaks to swimming coach, Rick Madge, about the reasons swimmers keep getting better results in the pool.

Also in the programme, photos of an overcrowded jail in the Philippines – taken by photographer Noel Celis – have gone viral. But remarkably some prisoners told him they felt ‘lucky’ to be there. They say many have met with a much worse fate as the new president Rodrigo Duterte cracks down on the country’s illegal drug trade.

And, why do we still fear animals that pose no serious threat to us and how can the effect of that irrational fear be so overpowering? Mike Williams discovers the answers lie deep in our evolutionary past.

(Photo: Britain's Adam Peaty swimming, credit: Reuters)

Is Iceland the best football team in the world per capita? England suffered a 2-1 defeat to Iceland in the European Football Championship in France. This was embarrassing for England whose population is 163 times bigger than Iceland’s. We take a look at whether Iceland is now the best performing football team in the world if you compare UEFA ranking to the size of each country’s population.

First came #Brexit, could #Frexit, #Ausexit or #Texit follow? The social media movements which have been inspired by Britain voting to leave the European Union are explained. And less than an hour after a terror attack in Istanbul, why did Turkey's government ban Facebook and Twitter? BBC Trending reports.

The bicycle - and cycling - started out as somewhat of a faddish leisure pursuit, largely the preserve of middle-aged and wealthy men. Yet it quickly became the world’s most popular means of transport and remains so to this day. Mike Williams explores its history and role in society for the Why Factor.

(Photo: England v Iceland, EURO 2016, Nice, France. Credit: Reuters)

Following a referendum, the UK has voted to leave the European Union. What might that mean for the UK’s economy, especially for trade? Tim Harford examines the economic forecasts from the government, and how the UK might manage its relationships with other countries for More Or Less.

Why have murder rates spiked in several US cities? The head of the FBI, James Comey, has asked whether police are holding back from their work through fear of being filmed on camera phones and going viral on YouTube. The theory has been dubbed the ‘Viral Video Effect’, or the ‘Ferguson Effect’ after the city that witnessed unrest after a black teenager was killed by a white police officer. BBC Trending reports.

Why are we attracted to some people and to not others? Beauty, facial symmetry, personality and values all play a role in our attraction to others. Evolution biologist Dr Anna Machin from Oxford University explains the science behind our feelings. Mike Williams presents the Why Factor.

(Photo: A pay-per-view binocular with the British and European Union flags. Credit: Sean Gallup/Getty Images)

In More Or Less Wesley Stephenson finds out how the search for new antibiotics is hampered not by science but by economics. Despite the $40 billion market worldwide there is no money to be made so big pharmaceuticals have all but stopped their research. Why is this and how do we entice them back in?

BBC Trending reports on the violence which has erupted over the use of Afrikaans at the University of Pretoria in South Africa. Some students want to see the language banned from lecture theatres, and say its presence is a form of racism. But others think it should remain. And a Hollywood actor – Terry Crews – has posted several videos to Facebook about fighting his addiction to pornography. It sparked a wave of support in online communities dedicated to abstaining from porn.

In the Why Factor Mike Williams asks why we search for the origins of life. He visits the Large Hadron Collider at CERN, where researchers from around the world have built the largest single machine on earth to discover some of the most extreme elements of nature, from the heart of an atom to the origins of the universe.

(Photo: Computer artwork of bacteria. Credit: Science Photo Library)