Colourism is a more insidious form of racism, and harms the prospects of finding work and love for people with darker skin around the world.

Natasha Pizzey reports from Mexico and Daniel Gallas reports from Brazil on the efforts to fight back against the prejudice against skin tone, which often emanates from within the same ethnic community as the victims. Meanwhile, Ed Butler speaks to Sunil Bhatia, a professor of human development at Connecticut College in the US, who has studied the rise of this phenomenon around the world.

(Picture: Two young black women with contrasting skin tones; Credit: PeopleImages/Getty Images)

People queue all night to get filthy notes in a country which is running out of cash. Lesley Curwen visits Harare, the country's capital and talks to those who have to spend all night outside the bank and who then often don't manage to get any cash. And also when they do it's so dirty that it's not accepted outside the country. Plus Monica de Bolle of the Petersen Institute research group in Washington tells Manuela Saragosa about the economic similarities between Venezuela and Zimbabwe.

(Picture: People queue outside a bank in Harare; Credit: Zinyange Auntony/AFP/Getty Images)

The usual western sponsors in this years World Cup have largely been replaced by Asian brands. Why?

FIFA makes most of its money from selling the broadcast rights to the World Cup, and through corporate sponsorship. But this year fans won't be seeing as many of the usual brands they're used to on billboards and adverts. Instead, they'll be seeing a lot of...well, Mongolian yoghurt as Simon Chadwick Professor of Sports Enterprise at Salford University in Manchester tells Manuela Saragosa. She also hears from Toby Hoare, CEO of J Walter Thompson in Europe, a marketing communications company which advises large global clients on how to manage their brands. Plus Sean O'Connor, co-founder of Statsports tells her about the tech players will be wearing this year.

(Picture: A girl standing in front of an advertisement by a Chinese dairy company sponsoring the 2018 Football World Cup, at a subway station in Beijing; Credit: Wang Zhao/AFP/Getty Images)

As G7 countries gather for trade talks in Quebec, could they gain some tips on how to fight back against the US steel tariffs from one of President Trump's favourite "sports" - WWE pro-wrestling?

Manuela Saragosa gets the views of Financial Times columnist and editor Rana Foroohar, and of William Alan Reinsch of the Washington DC think tank the Centre for Strategic and International Studies. Plus Adrienne Murray gathers the rather mixed feelings of Trump voters about the US President's trade tactics in the rusty steel town of Warren, Ohio.

(Picture: Donald Trump pushes WWE chairman Vince McMahon over, in the ring at a Wrestlemania event; Credit: Sam Greenwood/WireImage for World Wrestling Entertainment, Inc)

Zimbabwe is "open for business", claims its new President Emmerson Mnangagwa, but can it finally put its natural resources to good use?

The BBC's Ivana Davidovic reports on the country's diamond sector, which has been a source of popular resentment and corruption, while Vivienne Nunis speaks to the Australian company hoping to develop one of the world's biggest lithium deposits in the country. Back in London, presenter Manuela Saragosa speaks to economist Judith Tyson of the Overseas Development Institute about the country's prospects following the fall of Robert Mugabe.

(Picture: Mine worker with lithium ore; Credit: BBC)

Why do we behave the way we do in a group setting? Is it because of gender, because of taught behaviour or because of obligation? Ginny Smith, a science writer and memory expert, shows us how to make a “mind palace” to remember lists, and explains how the power of suggestion can affect how we remember things. What caused the last financial crisis? Some commentators suggest some of the blame can be placed on a male, testosterone-fuelled environment, but author Cordelia Fine says that ignores the real problem – bad decision making. Journalist Angela Saini says gender balance in science is not such a problem globally as it is in the west, which she says sounds paradoxical. But because modern science took off later elsewhere, in countries which already had votes for women, more women take part as a matter of course. Tax is a good topic when it comes to choice. Is how we think about fair shares of tax influenced by who we think about when it comes to tax avoidance? Yes, says Helen Miller of the Institute of Fiscal Studies. Vishala Sri-Pathma presents.

(Picture: Woman trying to remember. Credit: Getty.)

The real-world impact of the cryptocurrency business. Edwin Lane reports from Iceland, which has attracted power-hungry Bitcoin mines looking for a cheap source of electricity. Arni Jensen from the Borealis Data Centre shows him around a cryptocurrency mine near Reykjavik, and Johann Sigurbergsson from the geothermal energy company HK Orka describes the massive growth in the demand for electricity the miners have created. And the mayor of Plattsburgh, New York, Colin Read explains why his city is the first in the world to announce a temporary ban on cryptocurrency mining, amid concerns over its electricity supply.

(Photo: An illustration of Bitcoin mining, Credit: Getty Images)

He’s had a few outbursts in recent weeks. Calling stock analysts boring. Criticising his critics over the performance of his cars. Is he a genius, behaving like a playground bully, or both? Tim Urban, a US blogger who has interviewed Mr Musk, says his lack of a PR team means his opinions come unfiltered, but his innovations make him a genius. We also hear from Melissa Schilling, a professor at the Stern school of management and the author of Quirky: The Remarkable Story of the Traits, Foibles, and Genius of Breakthrough Innovators Who Changed the World. She says he shares a number of traits with Nikola Tesla, the namesake of his cars. Not everyone though is so enamoured. James Moore, chief business commentator for the UK's Independent newspaper, reckons he needs to engage with his critics rather than calling them names, or else run the risk of having them think they are right. Thomas Asterbro, professor of entrepreneurship at the HEC Paris business school, says his pioneership may not be such an advantage business-wise. Companies like Amazon and Facebook were not the first in their field, but they are now dominant.

(Picture: Elon Musk and Grimes attend the Heavenly Bodies: Fashion & The Catholic Imagination Costume Institute Gala at The Metropolitan Museum of Art on May 7, 2018 in New York City. Credit: Getty.)

Why are we being watched more and more by technology, including in the workplace? Is it an aid to hard work, or prelude to oppression? Wiretap co-founder Jeff Schumann creates software that monitors employee activity on workplace messaging apps. He says his technology is good, and can protect employees from backstabbing co-workers.

But to many, this technology has sinister potential. Professor Andre Spicer at Cass Business School in London says it is a reminder for employees of who is boss.

Ben Waber, president of a firm called Humanyze, tells presenter Ed Butler it has huge potential when it comes to spotting the previously unknown patterns of good productivity. Even having bigger lunch tables in the office canteen can increase output, as workers have more opportunity to chat and share ideas, he says.

(Photo: Giant surveillance desk with monitors. Credit: Getty Images)

Africa is developing economically, but its own companies don’t have the same profile as western brands. How come? Mary-Ann Kaikai of Madam Wokie Fashion, tells presenter Ed Butler about her dress designs in Freetown Sierra Leone. Her label made an impact on Hollywood red carpets, as well as in her home city. The Brand Leadership Group conducts survey each year of the continents' favourite 100 brands. This year's list came out last week, revealing once again that more than 80% of the names are Asian or western, such as Samsung, Levi's, and Coke. Only 19 were African. Thebe Ikalafeng, founder of the company, tells us more. So, what do African entrepreneurs need to do? Where can they get the experience to make a local product into an international one? That's where consultancies like De Charles come in. Ndubuisi Kejeh is a founding partner of this London-based firm, which aims specifically to build up African brands and what he calls it brand narratives for the continent.

(Picture: Mary-Ann Kaikai of Madam Wokie Fashion, and friend. Credit: Madam Wokie .)

MDMA, the key ingredient in the illegal party drug ecstasy, may soon be approved as a medicine. Meanwhile, it's also making a comeback across Europe's clubs and music festivals.

Manuela Saragosa speaks to neuropharmacologist David Nutt of Imperial College, who once got fired by the UK government for saying MDMA was less dangerous than horse-riding, and with psychedelic psycho-therapist Rick Doblin, who is seeking to get the chemical approved for the treatment of PTSD.

But while the drug may be safe in a clinical setting, dozens of people still die each year from taking illicit ecstasy pills. We hear from Andrew Cunningham of the EU drugs agency EMCDDA, and from Fiona Measham of the illegal drugs-testing service, The Loop.

Producer: Laurence Knight

(Photo: Ecstasy pills; Credit: portokalis/Getty Images)

Can artificial intelligence and face recognition technology be racist? AI is increasingly being used in all aspects of our lives but there is a problem with it. It often can't see people because of the colour of their skin. Zoe Kleinman speaks to Joy Buolamwini founder of the Algorithmic Justice League, Suresh Venkatasubramanian from the School of Computing at the University of Utah and Calum Chase, an AI expert and author about what is being done to overcome this problem. (Photo: Facial recognition system, Credit: Getty Images)