The answer, say researchers, is that not only do all human teenagers share similar characteristics, but their typical adolescent behaviour is reflected throughout the animal kingdom in creatures as small as insects to as large as whales.
Now the remarkable way human adolescent behaviour is mirrored in animals has been recorded in the new book Wildhood, written after years of research and worldwide travel by Harvard University evolutionary biologist Professor Barbara Natterson-Horowitz and science journalist Kathryn Bowers.
The pair studied the four universal challenges every adolescent of every species faces on the journey to adulthood: safety, status, sex, and survival.
“While every individual’s adolescent experience will differ in its details…when we started looking at adolescence across species, a universality presented itself,” they say.
“Adolescents from bottlenose dolphins to red-tailed hawks, clownfish to humans, have, in many ways, more in common with one another than with their mature parents or immature younger siblings.”
Here, Natterson-Horowitz and Bowers outline four of the behavioural traits human and animal adolescents share.
Human teens aren’t the only ones who take more risks and underestimate danger. The ‘problematic’ teenage brain – specifically the late maturation of the prefrontal cortex which by adulthood is able to contain impulses – is often used to explain higher adolescent rates of accidents, injuries and worse.
Strikingly similar brain biology during adolescence in other species pushes young wolves, possums, bears, and birds to take the risks needed to leave their dens, burrows and nests.
But this comes at a cost. Adolescent animals are disproportionately road-killed. Adolescent whales are more likely to be struck by shipping lane traffic. And lacking experience recognising and evading predators on their own, adolescent animals have some of the highest rates of becoming prey.
Consider the fledgling king penguins on South Georgia Island. After 15 months of care from parents, these adolescent penguins begin a crucial but hugely risky journey. Predator-naïve, pushed by their adolescent brain biology and the presence of their peers, they enter the icy water. They’re easy prey for leopard seals and orcas waiting for them offshore.
The statistics for fledglings aren’t good. But with experience they do become safer. In several species, adolescent animals exhibit behaviours which look risky but are actually adaptations to help them stay safer in the long run. Adolescent stickleback fish, bats, Thomson gazelles, and meerkats sometimes approach their predators instead of fleeing from them. This behaviour, called ‘predator inspection’, is at times dangerous, but the experience is crucial. The key is finding a way to gain experience while staying safe.
2. Social status
Popularity, Instagram followers, ‘likes’ – today’s teenagers seem obsessed with status, sometimes acting as if it were a matter of life or death. But they aren’t alone. For animal species who live in groups, status is a matter of life or death. In animal hierarchies, high status individuals eat more, live in safer places and reproduce more. They even have stronger immune systems and get better sleep.
Animal brains have evolved to signal when status is gained or lost. Like the physical pleasure which rewards animals for actions which increase survival and reproduction – eating and having sex – ‘status pleasure’ rewards animals when they rise up the ladder. The building blocks of the emotional centres in the human brain can be found in the brain status networks in fish, reptiles, birds and other mammals.
Status is extremely important in spotted hyena societies. High status hyenas (females rule the clans) have more food, alliances, and reproduce more. Lower status females and males are disadvantaged from birth. Status is one of the most powerful forces in the lives of adolescents across the animal kingdom.
After young humans go through puberty, their bodies are physically capable of creating babies. However, they are many years away from being ready for parenthood. Remarkably, when wild animals go through puberty many will not have sex for years. In some cases, they must learn complex courtship steps, songs, and sequences before they breed. Laysan albatross adolescents practise their courtship for four to five years for example. Novice sexual encounters between moths, horses, elephants and more have been characterised as fumbling and even awkward by wildlife biologists.
Across the animal kingdom, music seems to have a powerful romantic impact. Canary and dove songs performed just right can induce ovulation in females. But it takes a lot of practice. Humpback whale adolescent males are invited to join choruses of males who loudly croon complex music that draws females to them. In the beginning, the adolescent males don’t sing properly. With years of experience and practice, these whales become more powerful singers.
The songs and sequences of animal courtship are a complex language that takes time and practice to learn properly. Studies of the sexual lives of young wild animals confirm a species-spanning reality: sex is easy, courtship is hard.
Our own adolescents need help understanding how to connect and communicate deeply and how to maintain a relationship. For them too, learning about the mechanics of sex is relatively easy. Mastering sexual communication and romance is much harder.
Before they leave home, adolescent wolves go to ‘finishing school’, a term wolf biologists use to describe the adult hunts they’re invited to join. Young wolves initially eat whatever they can catch even if it’s low-quality food like mice and rats. But a few weeks after setting out, wolves are strong and experienced enough to take down larger prey.
Leaving home is dangerous for young birds and mammals. While predators are a significant threat, finding enough food is challenging for animals on their own for the first time. In many species, parents provide preparation – cheetah mothers disable gazelles and meerkat adults pull out scorpion stingers as practice prey for young hunters-in-training. But some learning can only happen when a young animal is hungry – literally a do-or-die situation.
Across the animal kingdom and as in humans, self-sufficiency doesn’t happen automatically. Preparation, practice, and hunger transform dependent young animals into self-reliant adults.