Now I want to answer a question posed (or at least implied) on Twitter, “I’d love to see all this, including other less-salient changes, through the lens of the decline of religion.” If religious people are more likely to disapprove of homosexuality, and if religious affiliation is declining, how much of the decrease in homophobia is due to the decrease in religion?
To answer that question, I’ll use the most recent GSS data, released in May 2023. Here’s the long-term trend again:
The most recent point is a small uptick, but it follows an unusually large drop and returns to the long-term trend.
Here are the same results divided by strength of religious affiliation.
As expected, people who say they are strongly religious are more likely to disapprove of homosexuality, but levels of disapprobation have declined in all three groups.
Now here are the fractions of people in each group:
The fraction of people with no religious affiliation has increased substantially. The fraction with “not very strong” affiliation has dropped sharply. The fraction with strong affiliation has dropped more modestly. The most recent data points are out of line with the long-term trends in all three groups. Discrepancies like this are common in the 2021 data, due in part to the pandemic and in part to changes in the way the survey was administered. So we should not take them too seriously.
Now, to see how much of the decline in homophobia is due to the decline of religion, we can compute two counterfactual models:
What if the fraction of people in each group was frozen in 1990 and carried forward to the present?
What if the fraction of people in each group was frozen in 2021 (using the long-term trend line) and carried back to the past?
The following figure shows the results:
The orange line shows the long-term trend (smoothed by LOWESS). The green line shows the first counterfactual, with the levels of religious affiliation unchanged since 1990. The purple line shows the second counterfactual, with affiliation from 2021carried back to the past.
The difference between the counterfactuals indicates the part of the decline of homophobia that is due to the decline of religion, and it turns out to be small. A large majority of the change since 1990 is due to changes within the groups — only a small part is due to shifts between the groups.
This result surprised me. But I have checked it carefully and I think I have an explanation.
First, notice that the biggest shifts between the groups are (1) the decrease in “not so strong” and (2) the increase in “no religion”. The decrease in strong affiliation is relatively small.
Second, notice that the decrease in homophobia is steepest among those with “not so strong” affiliation.
Taken together, these results indicate that there was a net shift away from the group with the fastest decline in disapprobation and toward a group with a somewhat slower decline. As a result, the decrease in religious affiliation makes only a modest contribution to the decrease in homophobia. Most of the change, as I argued previously, is due to changed minds and generational replacement.
Last week I published an excerpt from Probably Overthinking It that showed a long-term decline in homophobic responses to questions in the General Social Survey, starting around 1990 and continuing in the most recent data.
Then I heard from a friend that Gallup published an article just a few weeks ago, with the title “Fewer in U.S. Say Same-Sex Relations Morally Acceptable”.
It features this graph, which shows that after a consistent increase from 2001 to 2022, the percentage of respondents who said same-sex relations are morally acceptable declined from 71% to 64% in 2023.
Looking the whole time series, there are several reasons I don’t think this change reflects an long-term reversal in the population:
1) The variation from year to year is substantial. This year’s drop is bigger than most, but not an outlier. I conjecture that some of the variation from year to year is due to short-term period effects — like whatever people were reading about in the news in the interval before they were surveyed.
2) Even with the drop, the most recent point is not far below the long-term trend.
3) Last year was a record high, so a part of the drop is regression to the mean.
4) A large part of the trend is due to generational replacement, so unless young people die and are replaced by old people, that can’t go into reverse.
5) The other part of the trend is due to changed minds. While it’s possible for that to go into reverse, I start with a strong prior that it will not. In general, the moral circle expands.
Taken together, I would make a substantial bet that next year’s data point will be 3 or more percentage points higher, and I would not be surprised by 7-10.
Gallup makes it easy to download the data from the article, so I’ll use it to make my argument more quantitative. Here’s the time series.
The responses vary from year to year. Here is the distribution of the differences in percentage points.
Changes of 4 percentage points in either direction are not unusual. This year’s decrease of 7 points is bigger than what we’ve seen in the past, but not by much.
This figure shows the time series again, along with a smooth curve fit by local regression (LOWESS).
Since last year’s point was above the long term trend, we would have expected this year’s point to be lower by about 1 percentage points, just by returning to the trend line.
That leaves 6 points unaccounted for. To get a sense of how unexpected a drop that size is, we can compute the average and standard deviation of the distances from the points to the regression line. The mean is 1.7 points, and the standard deviation is 1.3.
So a two-sigma event is a 4.2 point distance, and a three-sigma event is a 5.4 point distance.
Of the 7-point drop:
1 point is what we’d expect from a return to the long-term trend.
4-5 points are within the range of random variation we’ve seen from year to year.
Which leaves 1-2 points that could be a genuine period effect.
But I think it’s likely to be short term. As the Gallup article notes, “From a longer-term perspective, Americans’ opinions of most of these issues have trended in a more liberal direction in the 20-plus years Gallup has asked about them.”
And there are two reasons I think they are likely to continue.
“At one time the benevolent affections embrace merely the family, soon the circle expanding includes first a class, then a nation, then a coalition of nations, then all humanity, and finally, its influence is felt in the dealings of man with the animal world.”
Lecky, A History of European Morals from Augustus to Charlemagne
Historically, the expansion of the moral circle seldom goes in reverse, and never for long.
The other reason is generational replacement. Older people are substantially more likely to think homosexuality is not moral. As they die, they are replaced by younger people who have no problem with it.
The only way for that trend to go in reverse is if a very large, long-term period effect somehow convinces Gen Z and their successors that they were mistaken and — actually — homosexuality is wrong.
I predict that next year’s data point will be substantially higher than this year’s.
This article is an excerpt from the draft manuscript of Probably Overthinking It, to be published by the University of Chicago Press in December 2023. It is available for preorder now from Amazon and other booksellers.
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This book is intended for a general audience, so I explain some things that might be familiar to readers of this blog – and I leave out the Python code. After the book is published, I will post the Jupyter notebooks with all of the details!
[This excerpt is from a chapter on moral progress. Previous examples explored responses to survey questions related to race and gender.]
The General Social Survey includes four questions related to sexual orientation.
What about sexual relations between two adults of the same sex – do you think it is always wrong, almost always wrong, wrong only sometimes, or not wrong at all?
And what about a man who admits that he is a homosexual? Should such a person be allowed to teach in a college or university, or not?
If some people in your community suggested that a book he wrote in favor of homosexuality should be taken out of your public library, would you favor removing this book, or not?
Suppose this admitted homosexual wanted to make a speech in your community. Should he be allowed to speak, or not?
If the wording of these questions seems dated, remember that they were written around 1970, when one might “admit” to homosexuality, and a large majority thought it was wrong, wrong, or wrong. In general, the GSS avoids changing the wording of questions, because subtle word choices can influence the results. But the price of this consistency is that a phrasing that might have been neutral in 1970 seems loaded today.
Nevertheless, let’s look at the results. The following figure shows the percentage of people who chose a homophobic response to these questions as a function of age.
It comes as no surprise that older people are more likely to hold homophobic beliefs. But that doesn’t mean people adopt these attitudes as they age. In fact, within every birth cohort, they become less homophobic with age.
The following figure show the results from the first question, showing the percentage of respondents who said homosexuality was wrong (with or without an adverb).
There is clearly a cohort effect: each generation is substantially less homophobic than the one before. And in almost every cohort, homophobia declines with age. But that doesn’t mean there is an age effect; if there were, we would expect to see a change in all cohorts at about the same age. And there’s no sign of that.
So let’s see if it might be a period effect. The following figure shows the same results plotted over time rather than age.
If there is a period effect, we expect to see an inflection point in all cohorts at the same point in time. And there is some evidence of that. Reading from top to bottom:
More than 90% of people born in the nineteen-oughts and the teens thought homosexuality was wrong, and they went to their graves without changing their minds.
People born in the 1920s and 1930s might have softened their views, slightly, starting around 1990.
Among people born in the 1940s and 1950s, there is a notable inflection point: before 1990, they were almost unchanged; after 1990, they became more tolerant over time.
In the last four cohorts, there is a clear trend over time, but we did not observe these groups sufficiently before 1990 to identify an inflection point.
On the whole, this looks like a period effect. Also, looking at the overall trend, it declined slowly before 1990 and much more quickly thereafter. So we might wonder what happened in 1990.
What happened in 1990?
In general, questions like this are hard to answer. Societal changes are the result of interactions between many causes and effects. But in this case, I think there is an explanation that is at least plausible: advocacy for acceptance of homosexuality has been successful at changing people’s minds.
In 1989, Marshall Kirk and Hunter Madsen published a book called After the Ball with the prophetic subtitle How America Will Conquer Its Fear and Hatred of Gays in the ’90s. The authors, with backgrounds in psychology and advertising, outlined a strategy for changing beliefs about homosexuality, which I will paraphrase in two parts: make homosexuality visible, and make it boring. Toward the first goal, they encouraged people to come out and acknowledge their sexual orientation publicly. Toward the second, they proposed a media campaign to depict homosexuality as ordinary.
Some conservative opponents of gay rights latched onto this book as a textbook of propaganda and the written form of the “gay agenda”. Of course reality was more complicated than that: social change is the result of many people in many places, not a centrally-organized conspiracy.
It’s not clear whether Kirk and Madsen’s book caused America to conquer its fear in the 1990s, but what they proposed turned out to be a remarkable prediction of what happened. Among many milestones, the first National Coming Out Day was celebrated in 1988; the first Gay Pride Day Parade was in 1994 (although previous similar events had used different names); and in 1999, President Bill Clinton proclaimed June as Gay and Lesbian Pride month.
During this time, the number of people who came out to their friends and family grew exponentially, along with the number of openly gay public figures and the representation of gay characters on television and in movies.
And as surveys by the Pew Research Center have shown repeatedly, “familiarity is closely linked to tolerance”. People who have a gay friend or family member – and know it – are substantially more likely to hold positive attitudes about homosexuality and to support gay rights.
All of this adds up to a large period effect that has changed hearts and minds, especially among the most recent birth cohorts.
Cohort or period effect?
Since 1990, attitudes about homosexuality have changed due to
A cohort effect: As old homophobes die, they are replaced by a more tolerant generation.
A period effect: Within most cohorts, people became more tolerant over time.
These effects are additive, so the overall trend is steeper than the trend within the cohorts – like Simpson’s paradox in reverse. But that raises a question: how much of the overall trend is due to the cohort effect, and how much to the period effect?
To answer that, I used a model that estimates the contributions of the two effects separately (a logistic regression model, if you want the details). Then I used the model to generate predictions for two counterfactual scenarios: what if there had been no cohort effect, and what if there had been no period effect? The following figure shows the results.
The circles show the actual data. The solid line shows the results from the model from 1987 to 2018, including both effects. The model plots a smooth course through the data, which confirms that it captures the overall trend during this interval. The total change is about 46 percentage points.
The dotted line shows what would have happened, according to the model, if there had been no period effect; the total change due to the cohort effect alone would have been about 12 percentage points.
The dashed line shows what would have happened if there had been no cohort effect; the total change due to the period effect alone would have been about 29 percentage points.
You might notice that the sum of 12 and 29 is only 41, not 46. That’s not an error; in a model like this, we don’t expect percentage points to add up (because it’s linear on a logistic scale, not a percentage scale).
Nevertheless, we can conclude that the magnitude of the period effect is about twice the magnitude of the cohort effect. In other words, most of the change we’ve seen since 1987 has been due to changed minds, with the smaller part due to generational replacement.
No one knows that better than the San Francisco Gay Men’s Chorus. In July 2021, they performed a song by Tim Rosser and Charlie Sohne with the title, “A Message From the Gay Community”. It begins:
To those of you out there who are still working against equal rights, we have a message for you […] You think that we’ll corrupt your kids, if our agenda goes unchecked. Funny, just this once, you’re correct. We’ll convert your children, happens bit by bit; Quietly and subtly, and you will barely notice it.
Of course, the reference to the “gay agenda” is tongue-in-cheek, and the threat to “convert your children” is only scary to someone who thinks (wrongly) that gay people can convert straight people to homosexuality, and believes (wrongly) that having a gay child is bad. For everyone else, it is clearly a joke.
Then the refrain delivers the punchline:
We’ll convert your children; we’ll make them tolerant and fair.
For anyone who still doesn’t get it, later verses explain:
Turning your children into accepting, caring people; We’ll convert your children; someone’s gotta teach them not to hate. Your children will care about fairness and justice for others.
Your kids will start converting you; the gay agenda is coming home. We’ll convert your children; and make an ally of you yet.
The thesis of the song is that advocacy can change minds, especially among young people. Those changed minds create an environment where the next generation is more likely to be “tolerant and fair”, and where some older people change their minds, too.
The data show that this thesis is, “just this once, correct”.
The General Social Survey (GSS) is a project of the independent research organization NORC at the University of Chicago, with principal funding from the National Science Foundation. The data is available from the GSS website.