Polling demonstrates that Americans tend to greatly overestimate the populations of subgroups within our general population. This includes estimates for religious minorities – such as Jews, Catholics or Muslims; racial and ethnic groups, such as Asian, Native, and black Americans; and income – those with household incomes over $500,000 and $1 million.

The overestimates include where people live, such as Texas, California and New York City, as well as the percentage of the population who identify as transgender, bisexual, or gay or lesbian.

On the flip side, people tend to underestimate the percentage in majority groups, such as Christians, whites, homeowners and those who have read a book in the past year.

The polling comes from YouGovAmerica, part of the British international market research and data analytics firm YouGov, headquartered in London.

The company explained the polls, saying, “In two recent YouGov polls, we asked respondents to guess the percentage (ranging from 0% to 100%) of American adults who are members of 43 different groups, including racial and religious groups, as well as other less frequently studied groups, such as pet owners and those who are left-handed.”

For religious groups, Americans estimated that 27% of the population was Muslim, with the true proportion being 1%; 30% was Jewish, with the real proportion being 2%; and 41% of the population was Catholic, while 22 percent is the real proportion. Those polled believed that 33% of the population was atheist, while only 3% of Americans identify this way.

As far as racial and ethnic groups, people guesstimated that 27% of us are Native Americans, 29% are Asian, 41% are black and 39% are Hispanic. Those numbers add up to more than 100%, because the surveys “don’t require people to make tradeoffs by constraining the sum of group proportions within a certain category to 100%.” The real percentages in those groups are 1%, 6%, 12% and 17%, respectively.  

When it comes to yearly income, those polled said that 20% of the population have a household income over a million and 26% have a household income over $500,000. In reality, about 1% of Americans make either of these amounts. People estimated that 30% of us live in New York City, 30% live in Texas and 32 percent in California, while the real proportions are 3%, 9% and 12%, respectively.

When it comes to various sexual identities, again, Americans seriously overestimate numbers, YouGovAmerica said, “including the proportion of gays and lesbians (estimate: 30%, true: 3%), bisexuals (estimate: 29%, true: 4%), and people who are transgender (estimate: 21%, true: 0.6%).” 

According to the organization, those in various minority subgroups “were no better (and often worse) than non-group members at guessing the relative size of the minority group they belong to.”

So where do these misconceptions come from? YouGovAmerica says that “observers have often attributed [this] to social causes: fear of out-groups, lack of personal exposure, or portrayals in the media.”

The pollsters don’t think this is a good explanation, saying, “Yet consistent with prior research, we find that the tendency to misestimate the size of demographic groups is actually one instance of a broader tendency to overestimate small proportions and underestimate large ones, regardless of the topic.”

Some might think that people inaccurately perceive “socially charged group divisions typically explored in similar studies: race, religion, sexuality, education, and income.”

But YouGov America says the same principle – of people overestimating minority subgroups and underestimating majority groups – also occurs when people are asked about less controversial topics, such as how many of us are left-handed, vegan or vegetarian, or military veterans. People estimated 30%, 34% and 40% for those groups, while the real percentages are 11%, 5%, and 6%.

Participants underestimated the size of larger groups in the U.S., such as those who identify as Christian (estimate: 58%, true: 70%), whites (estimate: 59%, true: 64%) and homeowners (estimate: 49%, true: 65%).

YouGovAmerica offers another explanation about why people are often so far off in population estimates, saying, “One recent meta-study suggests that when people are asked to make an estimation they are uncertain about, such as the size of a population, they tend to rescale their perceptions in a rational manner.”

The group explains, “When a person’s lived experience suggests an extreme value – such as a small proportion of people who are Jewish or a large proportion of people who are Christian – they often assume, reasonably, that their experiences are biased. In response, they adjust their prior estimate of a group’s size accordingly by shifting it closer to what they perceive to be the mean group size (that is, 50%).”

And how many people have read a book in the past year? While people guessed only 50% of the population has, the real proportion is closer to 77%.

You can read the YouGovAmerica survey results here.


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