A June 30 2021 tweet (part of discourse about transgender youth) referenced a “left-handedness chart,” as a rhetorical response to questions about why there were “suddenly” “so many” gay, transgender, and non-binary people:
'why are there suddenly so many gay/transgender/non-binary' people?
idk consult the left-handedness chart. pic.twitter.com/rhqJHglNbx
— Calvin Wong Tze Loon 黃子倫 🇲🇾 (@ithayla) June 30, 2021
A History of the ‘History of Left-Handedness’ Chart in LGBTQ+ Discourse
Although that tweet received significant engagement, it was not the first of its sort. A popular April 10 2021 Facebook post depicted an April 7 2021 tweet using the same graph to make a similar point:
Whenever I see people talking about the “skyrocketing” rates of people saying that they’re trans, I think of this chart. They used to punish children for being left-handed and force them to write with their right hand. Guess what happened after that stopped? https://t.co/YnY9j0jniv pic.twitter.com/Sq5gaiyOwR
— Ari Drennen (@AriDrennen) April 7, 2021
Alongside a slightly blurrier version of the same graph, Twitter user Ari Drennan specifically responded to a tweet claiming “the phrase ‘transgender ideology’ makes as much sense as ‘left-handed ideology.'” Drennan responded:
Whenever I see people talking about the “skyrocketing” rates of people saying that they’re trans, I think of this chart. They used to punish children for being left-handed and force them to write with their right hand. Guess what happened after that stopped?
Image comments featuring the same chart popped up on Reddit in May and June 2021. In April and June 2018, two separate tweets endeavored to make a point similar to the “History of Left-Handedness” chart posts:
The graph shows significant increases in left handedness over the past 100 years. Because people are no longer punished for being left handed. The apparent increase in numbers of trans young people is because there is more support for trans people to be themselves. pic.twitter.com/rPXbcpr3q2
— Trans Actual (@TransActualUK) April 12, 2018
TERFs claim that young people saying they’re trans is ‘social contagion’ 🙄
I guess that’d be like the ‘social contagion’ that occurred after left handed kids stopped being forced to write with their right hand and were allowed to use their naturally leading hand at school? 🤔 pic.twitter.com/vhDczTtmzQ
— Helen🏳️⚧️💙 (@mimmymum) June 18, 2018
Those tweets appeared to originate with users in the United Kingdom.
‘Left-Handedness Chart’ Source
Small text at the bottom of the chart indicated that it originated with a Washington Post sub-site, “Wonk Blog.”
A reverse image search returned a modest number of results (three), one of which was a September 2015 Washington Post piece, “The surprising geography of American left-handedness,” written by data journalist Christopher Ingraham.
Ingraham’s examination of trends in left-handedness over time in the United Stated did not occur at random. The article opened with a controversy involving a left-handed child in Oklahoma facing academic reprisal for being left-handed. (“Oklahoma Pre-K teacher allegedly calls being left-handed ‘evil’ and ‘’sinister.'”)
In his examination of left-handedness and historic societal disdain for the trait, Ingraham explained:
Regardless, it’s surprising that today, in 2015, a teacher would try to force a child to write with his non-dominant hand. Roughly 10 percent of people are left-handed, according Chris McManus, a University College of London researcher who wrote a book chapter on the history and geography of left-handedness … good data on the prevalence of left-handedness has been difficult to find, McManus writes.
One of the best available data sets on left-handedness comes from a scratch-and-sniff survey of olfactory ability mailed out to millions of National Geographic subscribers in the 1980s.
Go ahead and read that sentence again — it doesn’t get any less weird the second time around.
In 1986, National Geographic published a special issue on smell. As McManus recounts it, the issue “was accompanied by a ‘scratch and sniff’ card, which readers were encouraged to scratch, report what, if anything, they could smell, and then, after completing a brief demographic questionnaire, return the card.”
Ingraham prefaced the chart and its source data with the first paragraph, bookending it with the second:
Still, the sheer size of the database gave researchers a glimpse into the geography and history of left-handedness that they’d never had before. For starters, they show that rates of left-handedness fell during the late Victorian era, reaching their nadir in the early 1900s. They then rebounded steadily until about the 1950s or so, when they flattened out.
McManus theorizes that the late-Victorian dive in left-handedness reflects stigma against southpaws, of the kind that might have been on display in that elementary school in Oklahoma. He attributes a lot of that to the Industrial Revolution. “Left-handers may also have appeared less capable and more clumsy, as left-handed adults worked on machines that were almost certainly designed with right-handers in mind, and left-handed children were taught to write with steel dip pens that needed to be dragged across the paper from left to right by right-handers, and were not capable of being pushed across by the left hand without digging into the paper and making blots and stains.”
The article referenced a 2009 contribution [PDF] by researcher I.C. McManus, “The history and geography of human handedness,” to the larger work Language Lateralization and Psychosis. McManus explained in its introduction:
It is probable that about 8% to 10% of the population has been left-handed for at least the past 200,000 years or so. Detailed data only began to become available for those born in the nineteenth century, and there is growing evidence that the rate of left-handedness fell precipitously during the Victorian period, reaching a nadir of about 3% in about 1895 or so, and then rising quite quickly until an asymptote is reached for those born after about 1945 to 1950, with 11% to 12% of men and 9% to 10% of women typically being left-handed in Western countries. The sex ratio seems to remain constant, not only during historical changes but also with geographical differences, and is presumably the result of a biological rather than a cultural process.
In a section about historical data, McManus referenced the 1980s dataset:
Historical data on left-handedness are surprisingly rare, to the extent that a museum curator attempting to curate an exhibition on handedness referred to left-handers as being “a people without a history” (Sadler, 1997). Although estimating historical rates of left-handedness might seem easy, until recent years there has been very little systematic data. Modern work asking whether the historical rate of left-handedness might have changed systematically probably begins with that of Brackenridge (1981). However, quite the most important modern source on rates of left-handedness is the vast study by Gilbert and Wysocki (1992), which although never intended as a study of handedness has emerged 38 Section 1: Asymmetry, handedness and language lateralization as a key resource. In 1986, National Geographic magazine published a special issue on olfaction (Gibbons, 1986), which was accompanied by a “scratch and sniff” card, which readers were encouraged to scratch, report what, if anything, they could smell, and then, after completing a brief demographic questionnaire, return the card. Over 1.4 million people did so[.]
Another section addressed historical trends, and explained the manner by which left-handedness would have been directly and indirectly discouraged:
Social pressure can take many forms, and it is useful to distinguish between direct and indirect social pressure. Direct social pressure involves left-handed individuals being made to write with their right hand, as seems to have happened in some Victorian schools (see, e.g., Ireland, 1880), and has occurred in many other forms around the world to prevent left-handers using their left hands (see McManus, 2002).
However, direct social pressure of this sort only alters the phenotype, not the genotype, and the individuals still carry the genes that made them originally left-handed, and if transmitted those genes would allow those individuals’ offspring to become left-handed. Indirect social pressure is much more subtle, and does not directly alter the phenotype of the left-hander, but instead acts to make left-handers stigmatized, ostracized, and taboo, so that they find it harder to have offspring. The result is that their genes are less likely to be passed on, and hence the frequency of the genes responsible for left-handedness falls, and left-handedness becomes less common in the next generation.
To see how this might happen one must consider the very different social world of relatively small nineteenth-century communities, where most people knew one another, transport was less good, most people married people living less than 30 kilometers away, marriage was relatively early, as also was first childbirth, so that families were large, often with eight or ten children, child-bearing only ceasing at menopause. In such a world, any subtle denigration, mockery, or stigmatization of the left-handed, perhaps for clumsiness or awkwardness at writing or technical skills, or indeed for mere difference itself, might result in marriage and hence childbirth being delayed by five or ten years, so that the number of offspring would be reduced. The consequence would be a fall in the number of C alleles and hence in the rate of left-handedness. Indirect social pressure, although less brutal than direct social pressure, could be of far greater consequence in its eventual effects.
The since widely-shared Washington Post chart summarized in-depth research on the prevalence of left-handedness in the 20th century. Left-handedness appeared to drop to a level of around three percent at the turn of the century, slowly moving upward in the 1920s, and plateauing in the 1950s.
A Washington Post chart called “The history of left-handedness” entered discourse surrounding transgender youth in 2021, but historical patterns of left-handedness were similarly referenced going back to at least 2018. The chart was accurately labeled and based on in-depth research; its relevance to broader discussion could be seen as a matter of opinion. Nevertheless, the “left-handedness chart” and its underlying data were credible, and could fairly be construed as a demonstration of how cultural and social pressures (both direct and indirect) can alter the perception of the prevalence of inborn traits.