The unique appearance of each person on the planet is the cumulative result of generations of inherited traits, mixed with the quirks of chosen partners, to produce the next generation. While it’s common knowledge that skin colour, eye colour and hair colour are passed down, there are many other characteristics that travel the family line, sometimes with no obvious benefit. These oddball genetic gifts can spark endless conversation at family gatherings.

10 Strange Personal Traits Overview

Below we dive into ten of the most curious personal traits that you might not realise are part of your DNA. From the ability to roll your tongue to a sudden burst of white hair, each quirk has a story rooted in genetics.

10 Tongue Rolling

Roughly two‑thirds of the global population can curl each side of their tongue into a neat tube without breaking a sweat, while the remaining third are stuck with flat, non‑rollable tongues. This seemingly useless skill first caught the eye of genetic pioneer Alfred Sturtevant in 1940, who classified tongue‑rolling as a classic Mendelian trait – meaning it only needs one parent to pass on the gene, unlike blended traits. Other Mendelian examples include eye colour and freckles.

Surprisingly, the ability isn’t set in stone. With enough dedication, non‑rollers can learn to twist their tongues into a tube, though the motivation behind such practice remains a mystery. A study conducted by Delaware’s Department of Biological Sciences followed 33 non‑rollers for a month; only one participant mastered the “skill,” while the other 32 apparently opted out of the effort.

Genetics isn’t the sole factor, either. Some research shows that non‑genetic influences can affect tongue flexibility, and a handful of people fall somewhere in between – they can curl their tongues just a little, but not fully. In short, it’s a genetic oddity with a few outliers.

Weirdos.

9 Hairy Knuckles

If you’ve ever noticed a fine fuzz sprouting on the back of your fingers, right between the knuckles, you’re likely dealing with a hereditary trait rather than a secret superhero identity. Anthropologists have been cataloguing these stray strands for almost a century, noting that they most often appear on the ring finger and never on the thumb. While the trait seems most common among Caucasians, the underlying reason remains unclear.

Researchers suspect that prenatal exposure to androgens – the hormones that drive male characteristics – may be the catalyst. The hair‑on‑the‑knuckle trait behaves as a dominant gene, meaning a single copy from either parent can produce the fuzzy outcome, even though scientists have yet to isolate the exact gene responsible.

Given its quirky nature and the mystery surrounding its genetics, one could argue that this discovery deserves a Nobel Prize. Until then, the world will continue to marvel at the hidden fuzz on our fingertips.

Surely, there’s a Nobel Prize right there?

8 Hand Clasping

Every time you bring your hands together, you’re echoing a subtle family tradition. Most people naturally clasp one hand over the other, and research suggests that at least one parent likely shares the same preference. With only two options – right‑hand‑over‑left or left‑hand‑over‑right – the odds seem straightforward, but the science behind it is anything but.

Large‑scale studies reveal that about 55 % of individuals are left‑hand‑claspers, 44 % are right‑hand‑claspers, and a curious 1 % claim no preference at all. Geneticists have traced this pattern back to the same inheritance model that governs left‑ or right‑handedness, yet intriguingly, clasping preference appears unrelated to which hand is dominant.

Spooky!

Further investigations uncovered a link between hand‑clasping and arm‑folding habits, and even noted that menstruating women sometimes flip their clasping side during their cycle – a detail that sparked both giggles and eye‑rolls among scientists.

We are not even going to touch that joke.

7 Free Earlobes

If you stare closely at an ear, you’ll notice a surprising amount of individuality. While the overall shape and size of an ear can feel random, the earlobe’s form follows a clear genetic script. Everyone receives two copies of the earlobe allele – one from each parent – and these determine whether you sport a free‑hanging lobe or an attached one.

Earlobes may look decorative, but they serve a few practical purposes. Their generous blood supply can help keep the ear warm, and the dense network of nerve endings makes them an erogenous zone for many. The free‑lobe, which dangles beneath the head, is tied to a dominant gene, whereas the attached lobe, which sticks directly to the side of the head, stems from a recessive allele.

Neither type offers a clear evolutionary advantage; they simply exist as one of the many ways our bodies diversify. Because ears are weird.

6 Sneezing

Most sneezing, of course, is not genetic. Most often it is caused by a virus, an allergy, or environmental factors such as a dusty room. Some types of sneezes, however can have a genetic link.

Some people have an inherited sneeze reflex that is most often linked to exposure to bright light, but can be triggered by other causes too. This photic sneeze reflex, wittily dubbed ACHOO syndrome (which stands for “Autosomal dominant Compelling Helio‑Ophthalmic Outburst”, because “Genetically Induced Sneezing” just wasn’t funny enough), is thought to affect between 11 and 35 % of the population, with Caucasian females being most affected.

The sneezing is a dominant trait, meaning that if one of your parents has the syndrome, there is a 50 % chance that you will also have it. However, the syndrome often goes unrecorded because, well, people sneeze a lot. The exact gene responsible for these sneeze attacks has yet to be identified. People with the condition can expect to sneeze up to 40 times each time they walk into bright light, after which their body will adjust.

There is no treatment for the condition, though it can be managed with tissues.

5 A Bent Pinkie Finger

Although not always the result of genetics, a little finger that bows outward can often be traced back to family history. If you discover a crooked pinkie on your hand, a quick glance at your parents’ digits might reveal the same quirk – and with a 50 % inheritance chance, the trait can hop generations.

As with many “conditions,” the bent pinkie may also arise from non‑genetic sources like injury or disease. Researchers continue to debate how much of the angle is truly inherited versus how much is shaped by external factors. Determining the exact threshold for what counts as “bent” remains a challenge.

Clearly, much more work needs to be done in this vital area. The good news is that corrective surgery is available should the angle become acute, offering a straight‑handed solution for those who prefer symmetry.

4 A Widow’s Peak

It is generally known that male baldness can be linked to genes inherited from the mother. The X chromosome of the mother can contain a genetic predisposition to baldness, although it is not the only cause. Genes passed on from the father can also be a factor, although the chances are higher that the ‘faulty gene’ was passed by the mother where baldness occurs before the age of 40. Hair loss can also be caused by environmental factors, particularly smoking and drinking.

The case for a genetic cause of hair loss in a widow’s peak, however, is much stronger. The distinctive V‑shaped hair‑line is a dominant trait that can be passed on from father or mother, and both men and women can have a widow’s peak, although, it is much less noticeable in women because they do not tend to lose their hair.

The ‘peak’ refers to a triangular shaped hairline, which becomes more pronounced with hair‑loss. Although the peak is hereditary, it does not necessarily mean that baldness will follow as a result.

Although, it probably will.

3 A Long Second Toe

‘Morton’s toe’ is an inherited condition where the second toe is longer than the big toe, and occasionally, the third toe is also elongated. Estimates vary on the number of people who have the ‘condition’, which is named after an orthopaedic surgeon, rather than a man with unusually long foot digits, but it can affect anywhere between 3 % and 20 % of the population.

Morton believed that the long toe may have been a throw‑back to a pre‑human era when our ape‑like selves used a ‘grasping toe’. This theory, however, has never been proved. Shoe‑fitters are apt to call this shape the ‘Greek foot’ after the classical sculptures from Ancient Greece where the long second toe was considered the most aesthetically pleasing. The Statue of Liberty boasts a Morton’s toe.

It is not known whether she inherited it from her mother or her father.

2 A Shock of White Hair

A white patch of hair, usually at the front of the head, can be the result of an inherited trait. The streak is known as poliosis, or a ‘Mallen Streak’ after a family in a TV programme who all had a distinctive white patch of hair. Poliosis can affect not just the hair, but also the eyebrows, skin and even eyelashes.

Where the condition is not genetic, the patches may be a symptom of an illness. Despite popular myths, however, hair cannot turn instantly white from shock.

For those with inherited poliosis, there appears to be no associated conditions, and no downsides, except a distinctive look that is particularly favoured by devilish women with a penchant for spotty dogs.

1 Tone Deafness

Tone deafness, and its antithesis, perfect pitch, can both be inherited characteristics.

Known as Congenital Amusia (perhaps because it makes people laugh when you try to sing), inherited tone deafness is a condition in which sufferers are unable to recognize and distinguish musical pieces. They cannot recognize a song from its tune alone, and cannot detect when a song is sung out of tune. Studies have also shown that those with the condition are not able to detect a striking ‘bum note’ in a tune, an ability which most babies are able to demonstrate.

Although it can manifest as part of a brain injury, the vast majority of those who are tone deaf have no other symptoms, and suffer no hardships except being banned from Karaoke. Which is no hardship at all.

In particular, those with congenital amusia are unable to tell that they are singing out of tune themselves. Between 70 and 80 % of people who are tone deaf have the inherited condition, and around 4 % of the population are thought to be affected. Which, perhaps, explains the popularity of dubstep.

When you hear the phrase 10 traits you thought were exclusive to humans, you might picture a uniquely sophisticated species perched atop the evolutionary ladder. Yet, the natural world is brimming with creatures that flaunt these very same characteristics. From cultural knowledge to culinary creativity, animals have been quietly mastering the very traits we pride ourselves on. Below, we count down the ten most unexpected human‑like traits that have been documented in other species.

10 Sharing

Knowledge‑sharing, especially from one generation to the next, propels humans to the pinnacle of the food chain. It essentially defines culture. Yet this isn’t a uniquely human pastime. Baboons teach each other optimal foraging routes; fledgling birds master flight by observing their parents; and rats discern safe foods by smelling one another’s breath. Even fish benefit from the guidance of seasoned members in their schools. And it isn’t limited to social species—solitary animals display cultural foundations too. Young tortoises, for instance, learn to navigate novel obstacles by watching older conspecifics.

When a species vanishes, its cultural knowledge often disappears with it. The dwindling North Atlantic right whales, decimated by historic whaling, now lack the ancestral feeding‑ground wisdom of their forebears, further imperiling their survival. Culture isn’t always beneficial; entrenched, non‑adaptive traditions can misalign with shifting environments, steering a species toward extinction. Humans are currently confronting this very dilemma.

9 Weird Trends

In the era of TikTok, human fads grow increasingly bizarre. Yet, other animals also indulge in strange, time‑limited trends. White‑faced capuchin monkeys in Costa Rica display odd customs such as sniffing each other’s fingers and playing a game where one monkey bites off a clump of another’s fur, holding it in its mouth while the victim attempts to retrieve it. These traditions typically last about a decade—mirroring many human fashions—and tend to be highly localized, so a trend in one troop may never appear in another.

Most of these trends provide no obvious survival advantage. One particularly unsettling habit observed in a Costa Rican capuchin group involved inserting a dirty finger up to the first knuckle into a companion’s eye socket, just above the eyeball. The recipients wince, yet they neither resist nor discourage the act; instead, they seem to encourage it, allowing the behavior to persist for up to an hour. It resembles a painful tattoo or piercing, offering perhaps only a strengthening of social bonds.

8 Fashion

Beyond whimsical trends, the animal kingdom also embraces fashion. Bearded vultures, sporting pristine white feathers, dab iron‑rich soil onto their plumage—a form of makeup that signals status, with older, dominant birds sporting the most vivid coloration. Even fruit flies participate: virgin females show a preference for green‑dusted males after observing other females mate with them.

Chimps have also taken up sartorial statements. Since 2010, a chimpanzee in Zambia began inserting a blade of grass into her ear, a habit that quickly spread. Though it offers no clear survival benefit, the behavior proliferated across multiple groups, with four distinct communities adopting the grassy ear adornment.

7 Drug Use

Recreational drug use isn’t a human monopoly. Jaguars in the Amazon hunt down DMT‑laden yagé vines—the same ingredient used in ayahuasca brews. Lemurs indulge in narcotic millipedes, and dolphins chase high‑states by gnawing on pufferfish, then drifting upside‑down while gazing at their reflections.

Some animals become so enamored with their chosen substances they endure significant drawbacks. Bighorn sheep, addicted to lichen, grind their teeth down to the gums to scrape the nutrient‑rich mineral from rocks. Spider monkeys, intoxicated by fermented fruit, vomit and tumble from trees. An inebriated moose in Sweden famously became lodged in a tree after overindulging.

Drugs also serve as coping mechanisms for adverse moods. Rats confined to barren cages opted for sweetened morphine solutions over water, ultimately drinking themselves to death. Even fruit flies turn to alcohol when mate‑searching proves fruitless.

6 Facial Expressions

Smiles, frowns, and a rich tapestry of facial cues often feel uniquely human. Yet sheep not only display facial expressions, they also recognize them, distinguishing calm, startled, and fearful looks in fellow sheep and even differentiating between human faces. Domesticated dogs possess a similarly expressive repertoire, whereas their wild wolf ancestors exhibit a more limited range—suggesting selective breeding has honed interspecies communication.

5 Sense of Humor

Laughter likely didn’t spring from human imagination alone. Researchers propose it evolved from the panting sounds produced during playful fights among apes, a signal that the scuffle isn’t serious. Tickling a great ape today elicits a similar panting‑like laugh, indicating shared lineage.

Some apes display more sophisticated humor. Koko the gorilla, proficient in American Sign Language, once tied her trainer’s shoelaces together and signed “chase,” a mischievous prank. While some argue humor is universal among mammals, others suggest it extends even to insects. As we uncover deeper layers of animal cognition, the line between human and non‑human humor continues to blur.

4 Complex Language

Koko’s linguistic prowess also showcases an appreciation for complexity—when asked to name “hard” things, she responded with both “rock” and “work,” recognizing the word’s dual meaning. Surprisingly, the most intricate non‑human language resides not with great apes but with prairie dogs.

These highly social rodents emit distinct alarm calls for different predators—coyotes, hawks, humans—and attach descriptive modifiers detailing size, color, and other traits. This allows them to construct sentence‑like structures, and under laboratory conditions they can even describe novel objects they’ve never encountered.

While we’ve only begun to decode prairie‑dog chatter, their constant vocalizations suggest a rich, ongoing dialogue far beyond simple warning calls.

3 Storytelling

Storytelling feels like a hallmark of humanity—our primary vehicle for preserving culture, history, and imagination. Yet bees execute a form of narrative through their famed waggle dance, encoding distance, direction, route difficulty, and resource value to inform hive‑mates. This dance is essentially a shared story about food.

Dogs may also construct narratives when they paw at food bowls or scratch doors, indicating problem‑solving intentions and future plans. Some scientists speculate that dolphins could project 3‑D “sono‑pictorial holograms” using echolocation, crafting stories in a medium beyond our perception.

2 Spirituality

Jane Goodall observed chimps swaying rhythmically to waterfalls, then sitting in awe—behaviors reminiscent of human spirituality. Some chimp activities, like throwing stones to leave markings on trees, hint at ritualistic or perhaps religious undertones.

Across the animal kingdom, death ceremonies are surprisingly common. Elephants hold solemn processions when a herd member dies, attracting nearby herds that linger despite predator threats—a display of collective courage echoing human faith. Dolphins have been documented guarding a deceased female’s corpse for days, even fending off divers attempting to remove it, and protecting an infant’s body against seabirds.

Chimp mothers continue to cradle and groom deceased infants for weeks or months, only relinquishing them once decomposition is complete. Similar mourning rituals appear in gorillas, baboons, macaques, lemurs, and various bird species such as crows and jays.

1 Cooking

Fire revolutionized humanity, granting us warmth, expanded diets, and faster digestion. While no wild animal cooks with fire, some have demonstrated the ability. A bonobo learned to ignite a flame using fuel and matches supplied by researchers, then used it to grill burgers and roast marshmallows—later passing the skill to his offspring. Though the bonobo viewed a film about fire to spark the idea, it still mastered the technique, a feat many humans struggle to replicate under ideal conditions.

Culinary creativity extends beyond fire. Japanese macaques wash sweet potatoes before consumption, favoring salt‑water seasoning for added flavor. Pigs have been observed rinsing dirty apple chunks in streams. Shrikes impale prey on thorns or barbed wire, allowing it to decompose before eating. Capuchin monkeys sun‑dry palm nuts to facilitate cracking. Even ants engage in a form of cooking: big‑headed ants place food on larvae’s bellies, prompting the larvae to secrete enzymes that pre‑digest the meal.

Why 10 Traits You Should Care About

Understanding that the 10 traits you once believed set humans apart reveals the deep interconnectedness of life on Earth. It challenges anthropocentric views, promotes conservation empathy, and sparks curiosity about the hidden lives of our fellow creatures.