1. If you can write equally well with either hand, then you are the one percent. Even among the small population of ‘multi-handed’ individuals, very few experience equal ease and skill with both hands. In comparison, around 10% of people are lefties.
2. Right-, left- and mixed-handedness aren’t sufficient to define the preferences of most people, according to experts. Most people experience some level of cross-dominance — favoring one hand for certain tasks, even if it’s the non-dominant one — and among the group of people who use both hands, there are even finer distinctions. Ambidextral refers to those who can use both hands as well as a right-hander’s right hand (so, really well), and ambisinistral can be used to describe people who use both hands as well as a right-hander’s left hand (that is, somewhat clumsily).
3. Unlike righties, who show strong left brain dominance, the hemispheres of ambidextrous and left-handed people’s brains are almost symmetric...
4. ... as is the typical brain of a person with synesthesia, or “mixed senses,” who experiences cross-sensory perception. Among synesthetes, the instance of ambidexterity (and left-handedness) is much higher than in the general population.
5. The ambidextrous are more likely to possess the LRRTM1 gene (on chromosome 2), which is linked to schizophrenia. Studies reveal that people with schizophrenia are significantly more likely to be ambidextrous or left-handed than people who are not schizophrenic.
6. Another study, conducted through the BBC Science website, shows that of the one percent of 255,000 respondents who indicated equal ease writing with both hands, 9.2% of men and 15.6% of women reported being bisexual. In the same study, 4% of right-handed and 4.5% of left-handed men, and 6.2% of right-handed and 6.3% of left-handed women said they’re attracted to both sexes.
7. People who identify as ‘either-handed’ score slightly lower overall in general intelligence testing, and most often those scores are lower in arithmetic, memory and reasoning...
8. ... except when they aren’t. A study of 8000 children ages 7 and 8 shows that the 87 mixed-handed students had more pronounced difficulties in language skills, and at ages 15 and 16, the same students showed a higher risk of ADHD symptoms and performed academically under both right- and left-handed students from the same sample.
9. Ambis can be quick to anger, according to a study from Merrimack College, which suggests a higher interlinking of brain hemispheres found in ambidextrous and lefties. A follow-up study found that the increased hemisphere connections correlate to increased awkwardness, clumsiness and moodiness.
10. But inconsistent-handers can also be easier to sway emotionally. Montclair State University tested a group of right- left and either-handers for emotional stability. Their findings report that of the group, righties were hardest to coerce, and ambis were most likely to report a change in mood based on their surroundings, directed thought, and music.
11. It’s not all bad news for the handedness-ambivalent, though. Being able to use both hands with (almost) equal ease can really pay off, especially in sports, arts and music. Some reportedly cross-dominant celebrities and historic figures include Leonardo da Vinci, Pete Rose, Richard Feynmen, pitcher Greg A. Harris, Michelle Kwan, Shigeru Miyamoto, Paul McCartney, Benjamin Franklin and Harry Truman.