War for the Planet of the Apes, the latest movie in the enduring Planet of the Apes franchise, took the top spot at the box office on its opening weekend and is one of the biggest films of the summer.
As with all films in the franchise, which first launched in 1968, the plot of the 2017 movie is based largely on the assumption that apes could speak like humans if only they had a boost in brainpower—which, on the big screen, they receive via a synthetic drug.
But could apes really be just one pharmaceutical away from being able to talk like people?
It’s an enduring debate among scientists: whether non-human primates could speak with a little more brainpower, or whether they lack the proper anatomical structure in their vocal tract to produce human-language sounds.
It’s also an area of interest for primatologists Dieter and Netzin Steklis, who have spent decades working with apes, and lead the University of Arizona summer Primate Studies Field School in Rwanda.
The most recent debate on the topic to capture the attention of the Steklises is between Philip Lieberman, a cognitive scientist at Brown University, and William Tecumseh Sherman Fitch III, an evolutionary biologist and cognitive scientist at the University of Vienna.
According to Lieberman’s research, which uses models of primates’ vocal tracts, monkeys and apes are unable to produce the range and succession of vowel sounds required for human speech because of the way their vocal tracts differ from humans’. Humans have a longer tract in the form of an L-shape that evolved with upright walking.
Fitch and his colleagues, on the other hand, argue that an L-shaped vocal tract is not necessary for vowel production. They concede that monkeys and apes don’t have the full range of vowel production, and that if apes could talk, it would sound quite different from human speech. However, they believe the speech could still function as a meaningful language.
Dieter Steklis, a professor in the university’s School of Animal and Comparative Biomedical Sciences, and Netzin Steklis, a lecturer in the same school and in the family studies and human development department, have done their own research on language and vocalizations in apes.
Here, they offer their perspectives on the debate, as well as their thoughts on why the Planet of the Apes movies continue to be so popular.