On humans and other primates, nails are a flattened version of a claw which likely developed to aid in gripping and climbing. However, they can also act as a visible “health report.” Someone in poor health, or infected by a fungus, might have yellow, brittle nails, while someone in good health might have strong, long nails.

The fact that healthy nails are the sign of a healthy person may have led to people beginning to grow them out, or it could have been simply that long nails are cumbersome when working with your hands, so they were something of a status symbol. Whatever the case, it might surprise you to learn that manicuring nails has actually been around for many thousands of years—dating back at least to 3200 B.C. At the time, Chinese royalty would grow their nails and tint them with things like eggwhites or flower petals. Around the same time, Ancient Egyptians were also painting their nails, this time in accordance with their social classes; richer Egyptians painted their nails a darker colour, while poorer Egyptians painted them a lighter colour.

The modern practice of growing out and painting nails is a result of a more recent occurrence, happening in the 1920s and 1930s where women began growing long, luxurious nails. Before this, women commonly tinted their nails with oil or glosses. However, in the 1920s, shortly after the introduction and popularity of automobile paint, proper nail paint also became available and a nail painting boom resulted.

Of course, many “proper” women didn’t dare paint their nails for several decades after that, but Hollywood stepped in. In 1940, it became the style to have long, red nails, likely spurred on by actress Rita Hayworth. Many women started copying her style, striving to look like the knockout celebrity.

Much like painting one’s nails, artificial nails, which mimic real nails and add length and a healthy appearance to nails, have an astoundingly long history. Artificial nails were once worn by Chinese women during the Ming Dynasty (14th -17th century). In this case, these nail extensions were worn by noblewomen to further show that they did not have to use their hands for manual labour, unlike commoners. There are also records of women in 19th century Greece using pistachio shells as artificial nails.

It wasn’t until 1954 that an early version of the modern artificial nail was invented. It was first patented by Fred Slack, a dentist, who had chipped his nail at work and needed a replacement. He and his brother worked with various materials before coming up with something that would work, starting with dental acrylic, resulting in a realistic-looking fake nail that soon became incredibly popular among women across the world. Since then Slack’s company, Nail Systems International, has continued to innovate creating fake nails out of a variety of substances.

Of course, as with everything beauty and style related, growing nails out and painting them are trends that come and go. During the 1960s, women preferred a more natural look and rarely painted their nails. Nail painting saw a huge come-back in the 1980s, though, and since then the practice has been relatively popular in certain countries in the world.

If you liked this article, you might also enjoy our new popular podcast, The BrainFood Show (iTunes, Spotify, Google Play Music, Feed), as well as:

• When People Started Wearing Clothes
• The Origin of “Say Cheese” and When People Started Smiling in Photographs
• Why Nails on Your Fingers and Toes Grow at Different Rates
• Why We Toast Drinks
• When Men and Women Started Shaving Various Parts of Our Bodies

Bonus Facts:

• According to the Guinness Book of World Records, the woman who had the longest nails was Lee Redmond, a great-grandmother from the United States. She started growing her nails out in 1978 and manicured them regularly to get them to a length of roughly 30 inches each. (All ten nails have a combined length of 24ft, 7.8in, or 751.3 centimetres.) Lee lost her nails in a car accident in 2009. She reported that she got around just fine with such long nails, buttoning her coat, cutting her grandchildren’s hair, and driving a car with ease. Of course, she added that it was much easier to do all of those things now with her shorter nails. Lee also won’t be growing her nails out again, as it took her 30 years last time and she might not live for another 30, so the title of longest fingernails is up for careful grabs.
• Perpetual nail biters are called “pathological groomers.” It’s thought that nail biting can actually be lumped together with psychological disorders like OCD. Nail-biting can be a hereditary behaviour caused by a mutation on a gene, meaning people really just can’t help it, or it can simply be a learned behaviour or a product of anxiety. Either way, nail biters rarely have long nails.
• As you get older, your nails will likely grow more, but they won’t be quite as healthy as they were when you were younger. Older nails tend to be more brittle and duller in colour. In regards to aging toenails, those will become hard and thick. Senior citizens usually experience more nail-related issues, such as ingrown nails, than younger people due to this increased rate of growth.
• On average, fingernails grow about 3.5 millimetres per month, while toe nails only grow about 1.6 millimetres per month. Interestingly, the fingernails on your dominant hand likely grow faster than the fingernails on your non-dominant hand. Also, male fingernails usually grow faster than female fingernails, except when a woman is pregnant. Everyone’s nails grow faster in the summer than in the winter. Stress can actually slow down nail growth (as well as hair growth), as the nutrients and energy in the body are directed elsewhere.
• Nails really can tell a doctor a lot about your overall health. The colour of your nails can point to possible diseases you might have. For instance, a bluish tint might indicate lung disease, while a brown spot could be a sign of melanoma.
• White spots on nails are not caused by a nutrient deficiency, as is widely believed. Some people think that the white spots are caused by not having enough calcium or zinc in the system, but this just isn’t true. Instead, white spots are usually a sign of the nail suffering some trauma. Just think of your nail as a piece of plastic: when plastic is bent, it usually retains a white discoloration at the bend. The same is true of your nails.