The authors make clear that, in a fundamental sense, adolescent animals and teen humans encounter the same sorts of challenges - and that what may strike elders of any species as nutty, exasperating behavior is not only inevitable for most creatures in that stage of development but truly valuable.
Other scientists who have studied adolescents - human and nonhuman - echo their findings. Those elephants that charge right into harm's way? Their behavior is wholly in keeping with the adolescent modus operandi.
Human "adolescents frequently put themselves in danger deliberately," Natterson-Horowitz and Bowers write, adding: "Adolescent risk-taking is seen throughout the animal world."
The result, unsurprisingly, is that adolescence can be pretty dangerous for animals, ranging from fish to birds to mammals. For the youths that have big bodies but little life experience, there's a "spike in mortality . . . they are easy prey," Natterson-Horowitz said.
One reason is that they engage in behaviours that are risky but beneficial, Bowers said. An example is a practice called "predator inspection," or approaching predators rather than fleeing. The trade-off for the danger of proximity is that adolescent animals watch, smell and learn, accumulating all kinds of information that can keep them safer as adults.
"The idea that adolescents are hard-wired to take these risks can put a new spin on the knuckleheaded antics of our own human teens," Bowers said.
Teens seem driven to chase novelty and test boundaries in their own version of predator inspection, Bowers said: chalking up as many experiences as they can - the good, the bad, the ugly - before they leave the nest.
But before anyone leaves any nest ("dispersal," in scientific parlance), there's considerable time spent roving in battalions - marked by peak levels of peer pressure - and flirting with disaster. Indeed, scientists have documented and observed that adolescents of all stripes are more inclined to make perilous moves while with peers.
Laurence Steinberg, a psychology professor at Temple University, worked on two related studies - one involving mice, half of which were adolescents, drinking ethanol-spiked water, and another in which human teens played a video game that reproduced driving conditions. The results were strikingly similar.
"We found that in the presence of peers, adolescent mice drank more than they do when they're alone," said Steinberg, who has published several books on adolescence. "But we didn't find any such peer effects in adults, which is identical to the kinds of things we were finding in human experiments."
Steinberg said the teenagers in the simulated driving study also took more risks when others were around, regardless of whether they interacted with their peers. Just knowing there were other teens watching appeared to prompt the one behind the wheel to act more carelessly.
These findings dovetail with what Steinberg says is another multispecies adolescent hallmark: the desire to socialize.
"For the most part, human adolescents like to be with other adolescents. Juveniles in other species like to be with other juveniles. If I say that teenagers are social animals, I think the word 'animal' is just as important in that sentence as the word 'social.' "
Anyone who has seen a pod of dolphins swimming alongside a boat zipping across the sea or watched videos of dolphins interacting with one another might conclude that these playful critters are highly social. Ann Weaver, an animal behaviourist who studies bottlenose dolphins in the intercoastal waterway off the coast of St. Petersburg, Florida, would agree.
"We just got off the water," Weaver said in a recent interview. "We were out there for about three hours, and almost all the dolphins we saw were small gangs of teens."
Asked to compare the behaviours of dolphin gangs and gaggles of teenage people, Weaver thought for a moment. "They are at their most physically fit, they're the strongest they're going to be and they do everything with exaggeration," she said, adding that she considers adolescence on the water "a contact sport."
Dolphins are featured in "Wildhood," in which Natterson-Horowitz and Bowers go deep and wide in addressing the raft of species-spanning equivalents. But they focus on four individual animals - a king penguin, a spotted hyena, a humpback whale and a gray wolf - as they advance through adolescence. And this voyage, the authors find, hinges on mastering four fundamental skills: staying safe, negotiating social status, navigating sexuality and living as adults.
As moored in science as their book is, Natterson-Horowitz and Bowers acknowledge it was partially shaped by their personal experience. Each was raising an adolescent - the human variety - while working on the book.
"Having an adolescent at home, with all the drama and the ups and downs, particularly the moodiness - and social media was just coming into the picture - guided us in terms of what we wanted to look for, what we wanted to better understand in the wild to bring back to our homes," Natterson-Horowitz said.
"We were deeply informed by the need to answer those question for ourselves as parents, and then hopefully for other people who are raising adolescents."
