People have grown taller over the last century. A global study looked at the average height of the 18-year-olds in 200 countries in 1914 and 2014. The results reveal that while Swedes were the tallest people in the world in 1914, Dutch men have risen from the 12th place to claim top spot with an average height of 182.5cm. Latvian women, meanwhile, rose from the 28th place in 1914 to become the tallest in the world a century later, with an average height of 169.8cm.

James Bentham, a co-author of the research from Imperial College, London, says the global trend is likely to be due primarily to improvements in nutrition and healthcare. “An individual’s genes have a big influence on their height, but once you average over whole populations, genes play a less key role,” he adds.

A little extra height brings a number of advantages, says Elio Riboli of Imperial College. “Being taller is associated with longer life expectancy,” he says. “This is largely due to a lower risk of dying of cardiovascular disease among taller people.”

“But while height has increased around the world, the trend in many countries of north and sub-Saharan Africa causes concern,” says Riboli. While height increased in Uganda and Niger during the early 20th century, the trend has reversed in recent years, with height decreasing among 18-year-olds.

“One reason for these decreases in height is the economic situation in the 1980s,” says Alexander Moradi of the University of Sussex. The nutritional and health crises that followed the policy of structural adjustment led to many children and teenagers failing to reach their full potential in terms of height.

Bentham believes the global trend of increasing height has important influences. “How tall we are now is strongly influenced by the environment we grow up in,” he says. “If we give children the best possible start in life now, they will be healthier and more productive for decades to come.”

A computer programme can identify breast cancer from routine scans with greater accuracy than human experts, some researchers said. They hoped what they developed could prove a breakthrough in the fight against the global killer.

Breast cancer is one of the most common cancers in women, with more than 2 million new diagnoses last year alone. Regular screening is vital in detecting the earliest signs of the disease in patients who show no obvious symptoms.

In Britain, women over 50 are advised to get an examination of a breast every three years, the results of which are analyzed by two independent experts. But interpreting the scans leaves room for error, and a small percentage of all mammograms(乳房X光检查) either return a false positive—misdiagnosing a healthy patient as having cancer—or false negative—missing the disease as it spreads.

Now researchers at Google Health have trained an artificial intelligence model to detect cancer in breast scans from thousands of women in Britain and the United States. The images had already been reviewed by doctors in real life but unlike in a clinical setting, the machine had no patient history to inform its diagnoses. The team found that their AI model could predict breast cancer from the scans with a similar accuracy level to expert radiographers.

Further, the AI showed a reduction in the proportion of cases where cancer was incorrectly identified—5.7 percent in the US and 1.2 percent in Britain, respectively. It also reduced the percentage of missed diagnoses by 9.4 percent among US patients and by 2.7 percent in Britain.

“The earlier you identify a breast cancer, the better it is for the patient,” Dominic King, UK lead at Google Health, told AFP. “We think about this technology in a way that supports and enables an expert, or a patient ultimately, to get the best outcome from whatever diagnostics they’ve had.”

Telling jokes requires intelligence, creativity, imagination and the ability to tell a story, while listening to jokes is more passive behaviour but one that demands attention, intelligence and being in the right mood in order to enjoy jokes. Besides, there are also clear similarities between joke tellers and appreciators. A new study takes this further and tries to find other connections between creating humour and appreciating humour.

The author carried on the cartoon caption (字幕) task. 159 participants were shown more than 30cartoons without captions and were asked to come up with a funny caption for each one of them. Later, independent judges classified those captions based on how funny they were.

The results showed that those who produced the funniest captions also produced more captions overall. What was more interesting was that creating funny captions was negatively related to appreciation of humour. In other words, funny people tend to find jokes less funny than other people do. It is not clear why this is the case, but it might be because creators of great humour have higher standards of humour creativity and expect higher levels of creativity from people who tell jokes, compared to those who are not so good at creating humour.

Moreover, outgoing people and those who are open to new experiences found the cartoons funnier, but surprisingly, outgoing people are less likely to be funny. This is consistent with my own research that comedians were more introverted than the general population. They usually don’t like to express themselves in social situations.

Appreciation and production of humour are two different cognitive (认知的) tasks, each with unique characteristics. This is why when someone tells you he or she has a great sense of humour, you may ask, “Are you good at telling jokes or do you tend to laugh more?”