Congratulations to Allogenes, who correctly answered that UUism in the 1960s was 90% composed of converts. In 1967 Robert Tapp reported the results of his comprehensive survey to the UUA: among his findings, only 10.6% of Unitarian-Universalists had been born into Unitarian/Universalist/Unitarian-Universalist families. The other near 90% were converts. Thirty years later, a UUA survey released in 1997 again found that UUism is composed of 90% converts and only 10% lifelong adherents.
This seems to put the low retention rate of birthright UUs into some perspective. It isn’t simply a crisis of the last decade or so: liberal religion appears to have a near rock-bottom retention rate. Furthermore, we have a third data point: Robert Miller’s scientific study of UUism published in 1976 found that 15.7% of UUs were lifelong members, while 84.3% were converts. 15% is nearly half-again as large as 10%, but we’re dealing with low numbers that approach the margin of error here, so let’s just say that throughout the second-half of the 20th century UUism had a cradle UU retention rate of about 10-15% and an incoming conversion rate of about 85-90%. This is remarkably steady, and it is worth noting that 1967 and 1997 were both periods of growth for UUism as a denomination.
Why is UUism so bad at retaining its children? Many ideas could be advanced here. Sociological theory posits that churches that make high demands on their members have much higher retention rates than ones with low barriers to joining and leaving and that do not make strong demands on how individual members order their lives, spend their resources, and think. That is to say, the liberal model is a losing model from a sociological standpoint, while the conservative model is a far stronger one. Yet at the same time it is impossible for either model to fully capture the market in an open situation such as exists in North America, and therefore even less healthy models (such as the liberal one) can maintain an apparently permanent position even in the face of competition from more robust approaches to member retention.
Put another way: UUism doesn’t make you pay for leaving. You aren’t damned to hell, shunned by your family or community, or harassed by former associates. The “exit costs” are minimal, and therefore little keeps people within UUism other than simple agreement with its principles or lack of a better alternative. This contributes to a high deconversion rate, simply because people are allowed to drift and suffer no penalties for leaving.
On the other hand, maintaining a UU identity requires little work and this too contributes to low UU retention. Sociologists have shown that people are substantially more faithful to churches that make high demands on their members–in many cases, the higher the demands, the greater the retention rate. Many people seem to want their religion to truly challenge them and force them to adopt a quasi-countercultural stance–membership in a church that speaks against the secular world in some fashion gives people a counterbalance to the pull of irreligious popular culture. The retention is highest among groups that don’t just talk the talk, but make you walk the walk by repudiating mainstream culture in defined ways, such as through one’s dress, speech, reading/viewing habits, social relations, and especially in how often one is expected to go to church and how strongly one is told to donate to church and similar good causes. Put yet another way: demands for personal sacrifice actually result in significantly higher retention of members in American churches (and likely elsewhere as well). Meanwhile, staying UU requires very little of the average members, and this contributes to people falling away either out of lack of interest, or attraction to more demanding (and therefore, by sociological measures, more rewarding) religions.