Top stories: ‘Extreme male brain’ does not cause autism, a lost Maya city, and disappearing sharks

By Eva FrederickSep. 6, 2019 , 3:05 PM

Study challenges idea that autism is caused by an overly masculine brain

Of the many proposed triggers for autism, one of the most controversial is the “extreme male brain” hypothesis. The idea posits that exposure to excess testosterone in the womb wires both men and women to have a hypermasculine view of the world, prioritizing stereotypically male behaviors like building machines over stereotypically female behaviors like empathizing with a friend. Now, a study is raising new doubts about this theory, finding no effect of testosterone on empathy in adult men.

In search of the ‘white jaguar’: Archaeologists travel deep into the jungle to find a lost Maya city

After repeated attacks by Spanish soldiers, hundreds of Lacandon Maya retreated deep into the Mexican jungle more than 400 years ago. There, they built a new city named Sac Balam, or “the white jaguar.” When the Spanish finally found Sac Balam in 1695, they forcibly removed its people, and it faded back into the forest; to this day, no one knows exactly where its ruins lie. But that may soon change, as archaeologists, accompanied by Science, set out into the Montes Azules Biosphere Reserve to find the lost city.

Great white sharks have suddenly disappeared from one of their favorite hangouts

Sightings of white sharks have crashed this year in False Bay near Cape Town, South Africa—one of the best-known hot spots of the predators in the world—and scientists aren’t sure why. Orcas, which love to dine on shark liver, may have scared them off, researchers say, but human activities could also play a role.

Human speech may have a universal transmission rate: 39 bits per second

Italians are some of the fastest speakers on the planet, chattering at up to nine syllables per second. Many Germans, on the other hand, are slow enunciators, delivering five to six syllables in the same amount of time. Yet in any given minute, Italians and Germans convey roughly the same amount of information, according to a new study. Indeed, no matter how fast or slowly languages are spoken, they tend to transmit information at about the same rate: 39 bits per second, about twice the speed of Morse code.

Humans haven’t just changed what dogs look like—we’ve altered the very structure of their brains

In the thousands of years we’ve lived with dogs, we’ve transformed them from fearsome wolves into fluffy, tail-wagging Frisbee catchers, which range in size from tiny Pomeranians to towering great Danes. Now, a new study of dogs’ brain scans suggests our impact on our canine pals has been even more profound: We’ve changed the very structure of their brains.