Only an estimated 10% of the global population are left-handed, and they face particular challenges in a world largely designed by and for righties.
If you're the parent of a left-handed child, you may therefore have some concerns.
Here are answers to a number of pertinent questions.
The origin of handedness – the tendency to use one hand more naturally than the other to perform activities such as writing or throwing a ball – isn't fully explained.
It's an example of what's known as laterality, which is specialised functioning in each hemisphere of the brain.
The right hemisphere controls the left side of the body, and vice versa.
Several factors probably cause a person's left hand to become the dominant one.
Children with left-handed parents are more likely to be left-handed themselves, which points to a genetic component.
Researchers at Ruhr University Bochum (RUB) in Germany found that handedness is established during formation of the spinal cord.
As early as the 13th week of pregnancy, embryos already show a preference to suck either the right or the left thumb.
Handedness manifests itself early in some children, while in others, it remains unclear for a long time.
You should be attentive to which hand is dominant, but not talk about it in front of the child "so as not to influence their behaviour", advises psychotherapist Johanna Barbara Sattler, who founded Germany's first counselling centre for left-handers in 1985.
The hand a child holds a pencil or spoon with doesn't necessarily mean much, according to Sattler, because "children often unconsciously conform to their right-handed environment".
Some young lefties, without being aware of it, train themselves to be righties so that they don't stand out.
Parents should pay more attention to spontaneous actions, such as which hand the child points to things or scratches their nose with.
And don't put their spoon to the right of their plate at mealtimes, but rather in the middle of their plate so they can spontaneously grab it with their preferred hand.
If you can't determine whether your child is right- or left-handed, Sattler recommends professional testing well before the child starts school.
This could save natural lefties the trouble of using right-handed scissors at a craft table.
And writing exercises for left-handed, first-year pupils are easier if they know they've got to tilt the paper to prevent smudging the ink.
The world is geared to righties – kitchen utensils, tools and machines are all designed so that right-handers can operate them easily.
Recessed handles are on the right-hand side, so lefties are either forced to reach over with their dominant hand or use their non-dominant one.
"But you're slower and less dexterous when you can't do things with your dominant hand," says Sattler.
"One brain hemisphere is underchallenged, the other overchallenged."
Many left-handers are unaware that a wide range of implements are now available that meet their special needs, says Heiko Hilscher, managing director of a shop in the German city of Erfurt that caters to lefties.
Products include fountain pens, scissors, knives, tin openers, computer mice and keyboards.
Some useful items are missing though, e.g. cameras with the shutter release on the left.
Yes, on the positive side, lefties have an advantage, and are disproportionately successful, in one-on-one sports such as tennis, table tennis, fencing and boxing, according to scientists at the University of Kassel in Germany.
The reason, they presume, is that most athletes are motorically less accustomed to left-handed opponents.
They also postulate that since European languages are written from left to right, people from these cultural backgrounds perceive stimuli in their left visual field better than in their right.
Consequently, they react more slowly to left-handed attackers, whose lead – or striking – hand is in their right visual field.
In any case, says Sattler, you should throw a ball or swing a racket with the hand that does it best.
You should also kick a ball with your stronger foot, which is your left one if you're left-handed.
Music lessons can be a challenge for left-handers because "musical instruments are designed for right-handers", points out Andrea Arnoldussen, a music teacher who works with left-handed pupils and is left-handed herself.
Even if your hands seem at first glance to be equally involved in playing an instrument, it makes a difference which hand is your dominant one, she says.
When you play the flute, for instance, your right hand not only closes the finger holes, but also stabilises the instrument.
"This is more difficult for left-handers," Arnoldussen says. "They instinctively hold their flute the other way around."
And the melody line in piano music is normally written for the right hand.
For lefties, the left hand would be better suited to this.
There are left-handed models for some musical instruments, including flutes, recorders and guitars.
Stringed instruments played with a bow can be modified by a violin-maker so that the musician's left hand wields the bow and the right hand holds the instrument's neck.
"Especially in the beginning, it's important that music pupils be allowed to try out the way they'd intuitively hold the instrument and feel most comfortable with," Arnoldussen says. – By Eva Dignös/dpa