Religious Influences on Mormon Fertility

Cross-National Comparisons

Tim B. Heaton

Tim B. Heaton, “Religious Influences on Mormon Fertility: Cross-National Comparisons,” in Latter-day Saint Social Life: Social Research on the LDS Church and its Members (Provo, UT: Religious Studies Center, Brigham Young University, 1998), 425–440.

Tim B. Heaton is professor of sociology at Brigham Young University. This article was originally published in Review of Religious Research 30:401–11; reprinted with permission.


This study examines patterns of religious influence on Mormon fertility in four countries. Religious ideology, religious reference groups, and socialization in a religious subculture are each avenues through which religion promotes larger families, but the patterns of influence are different in each country. The size of Mormon families relative to national patterns and the effects of independent variables on fertility vary across countries. Although pronatalism appears to be a common theme, its expression changes with cultural context.

Prior research demonstrates the complex nature of religious influences that maintain high fertility among Mormons in the United States (Heaton 1986). Not only does acceptance of a pronatalist ideology increase fertility, but contacts within a Mormon reference group and socialization into a pronatalist subculture also play an important role in predicting larger family size. The Mormon pronatalist theology centers around the concept of eternal families. Marriage and childrearing are viewed as a means of providing homes for God’s children, as a learning ground for spouses and parents, and as the formation of family bonds which will persist in the eternities (see Heaton 1987 for a discussion of the influence of theology on Mormon family life). These ideals are embodied in marriage ceremonies performed in Mormon temples.

In the United States, this theology is reinforced by interaction in local religious communities. Moreover, being raised as a child in a Mormon subculture helps perpetuate pronatalism. Supporting this model, evidence shows that Mormon temple marriage (acceptance of ideology), frequent attendance at religious services (contact with religious reference group), and growing up in a larger family with participating Mormon parents (socialization) are associated with larger family size. This paper ascertains whether these patterns of religious influence persist when proselytizing efforts lead to membership growth in different cultural and social settings. To do so, we will compare the effects of various aspects of religious experience on Mormon fertility in four different countries—United States, Britain, Japan, and Mexico.

The Mormon Church (The Church of Jesus Christ of Latter-day Saints or LDS) was founded in New York in 1830. Subsequent conflict led to eventual settlement in the Great Basin. Even now about half of the membership resides in the western United States. Over the last few decades, however, proselytizing efforts have generated substantial growth. A mission was established in Great Britain in 1837, and although the missionary effort was successful, many of the converts immigrated to the U.S. (Evans 1984). British Mormon membership remained relatively low during the first half of this century, but since then has grown at a rapid pace (Cuthbert 1987). Of the non-U.S. countries considered here, Britain has the longest tradition of Mormon influence. Nineteenth-century missionary contact in Mexico also met with some success, but Mexico’s political turmoil and the associated loss of contact with Church leadership inhibited long-term missionary work (Tullis 1987). Missionary efforts began in Japan at the turn of the century, but were unsuccessful (Cowan 1985). In each of the three countries, most membership growth occurred since 1960 (see fig. 14.1). Between 1970 and 1985, membership increased by 80 percent in Britain, over 300 percent in Mexico, and nearly 600 percent in Japan (Deseret News 1975, 1985).

LDS Church Membership: Great Britain, Mexico, and Japan

Although Mormon missionary proselytizing procedures vary somewhat from time to time and place to place, the standard approach involves a series of approximately six or seven lessons covering the basic beliefs of the LDS Church. After receiving these lessons, potential converts are encouraged to join as soon as they are willing to accept the responsibilities of membership. Thus, growth outside the U.S. has been too recent to allow the establishment of strong local religious traditions within the Mormon membership, and church contact with new converts prior to baptism is not extensive enough to integrate new members into a religious community. Just as converts to Christianity in Japan and Mexico maintained many of their non-Christian beliefs and customs, new converts undoubtedly retain many of their beliefs and customs after joining the Mormon Church. The question is, does religious involvement influence fertility behavior even under these circumstances?

The national patterns of fertility in the countries considered here provide very different contexts for Mormon fertility. Britain achieved low fertility even before the U.S., and birth rates are currently near the replacement level (Nissel 1982). The fertility decline in Japan was more recent and rapid; and although Japan now qualifies as a low fertility society, the timing of family formation remains distinctive (Fukutake 1981; Morgan et al. 1984). Mexico sustained high fertility rates up through 1970. Since then fertility has dropped dramatically, but remains well above levels in more developed countries (Alba and Potter 1986). Moreover, Mexico is the only country included in our analysis where the dominant religion still takes a strong pronatalist position. In short, the broader social milieu surrounding fertility behavior is very different in the four countries considered.

Due to the cross-national differences in the development of the LDS Church and in the societal patterns of fertility, we cannot expect similar Mormon fertility behaviors in each country. Even though the basic Mormon theology supporting pronatalism remains constant, the degree to which pronatalist Mormon subcultures have developed in each country and expectations and support provided by the local Mormon reference group are not necessarily similar across countries. Given the diversity of contexts combined with common membership in a western-centered pronatalist religion, we are interested in examining the impact of religious involvement on fertility in these four countries. In other words, we want to see how Mormonism interacts with local cultures in influencing fertility.

Independent variables

Several factors will be included which may affect fertility. Marriage in a Mormon temple implies acceptance of and commitment to the distinctive theology of the family. Frequency of church attendance indicates contact with a Mormon reference group. Having Mormon parents and age at baptism reflect the degree of socialization within the Mormon community (Heaton 1986), and coming from a larger family (e.g., more siblings) reflects socialization toward having children regardless of parents’ religion. Baptism at younger ages implies more exposure to Mormon theology prior to childrearing. [1] Husband’s religious affiliation reflects couples’ consensus on religious orientation: non-Mormon husbands will generally not be as supportive of particularistic modes of Mormon behavior (i.e., having large families). Temple marriage, frequent church attendance, coming from a large family, having Mormon parents, and early baptism are each expected to increase family size. The major focus of this analysis is determining whether these aspects of religious involvement have similar effects on fertility in each of the four countries. Finally, wife’s education, age at marriage, and marital duration are included as sociodemographic control variables.


Data collection for the Mormon surveys was initiated in the summer of 1981 and completed by the end of 1984. In the U.S. and Britain, questionnaires were mailed to a random sample of adults (aged eighteen and over) drawn from a computerized membership list maintained at LDS Church headquarters. A reminder postcard was sent out two weeks later. In the U.S. and Britain, additional efforts were made to interview nonrespondents using local volunteers and, in the U.S., telephones. If these efforts failed, bishops (local lay-ministers) were asked to provide information such as age, education, occupation, and frequency of church attendance if the information was available to the bishop. This procedure yielded a response rate of 81 percent in the U.S. and 60 percent in Britain.

Pretests indicated that these procedures would be ineffective in Mexico and Japan. Thus, a cluster design was used to sample ninety-four different congregations in seven major cities of Mexico, and fifty-nine different congregations in five major cities of Japan. The survey was administered to all adults who attended church services on a selected Sunday. A random sample of nonattenders was then taken from the local membership roster. Individuals were trained and instructed to contact this sample of nonattenders. If completed questionnaires or interviews could not be obtained, bishops were asked to fill in the information at their disposal. These responses were then weighted to reflect the relative size of the nonattending population. Weighted values are readjusted such that the weighted sample size equals the number of completed questionnaires.

The use of different data collection procedures raises the issue of comparability. Although there is not an explicit method of addressing this issue, two steps were taken to reduce cross-national differences which could arise from methodological procedures. First, questionnaires were very similar in form and content in each country. Following a census type format allowed the creation of questionnaires which were similar across countries, and also similar to census forms used in each country. Thus, the questionnaires are standardized across countries, but are in a form familiar to respondents in each country. Second, the weighting procedure adjusts for the frequency of attendance at religious services and the related differential response rate in each country. In Mexico and Japan, nonattenders were given a different probability of being sampled, which is taken into account in the weighting procedure. Note that most respondents in each country filled out the survey on their own. Whether or not reliance on the mailing systems in the U.S. and Britain affects response rates and patterns in a different way than the more personal method of distribution in Mexico and Japan cannot be ascertained.


Mormon fertility differs from national patterns in each of the four countries. Prior research has already documented high fertility associated with religious behavior in the United States (Heaton 1986; Heaton and Goodman 1985). Table 14.1 compares Mormon and national patterns in the other three countries. Since different types of national data are available in each country, it is not possible to present identical Mormon-national comparisons for each country. Available information indicates that Mormons have above average fertility in Britain and Japan, but the Mormon-national differences are probably not as different as they are in the United States. Apparently Britain and Japan have not developed the pronatalist tradition and cultural orientation to the degree that U.S. Mormons have.

A very different pattern appears in Mexico where Mormons have smaller families than the national average. Part of this difference could be due to the recency of the Mormon data (fertility is declining in Mexico) and the over-representation of urban residents. Still, these factors could not explain why Mormon fertility is not higher than the nation as is the case in the other three countries. Lower Mormon fertility suggests that joining an economically successful U.S.-based religion may be associated with upward mobility, or at least greater aspirations in Mexico. Thus, joining the Mormon Church and reducing family size may be related.

Relationships between children ever born and religious-demographic variables are presented in table 14.2. Mexico has the largest family size with an average of 3.5 children. The U.S. is not too far behind with a mean of 3.3 children. Britain is substantially lower with a mean of 2.8, and Japan is much lower with fewer than two children per family. Of course, some of this difference arises because of differences in marital duration and age at marriage. With the use of values in table 14.2 for adjustment, if women in each country had an average marital duration of fourteen years and an average age at marriage of twenty-two, then the average children ever born would be 3.19 in the U.S., 2.69 in Britain, 2.25 in Japan, and 3.82 in Mexico. Although data from four countries does not allow us to generalize, a logical pattern does seem to appear. In developed countries, Mormon fertility appears to fall above the national average, but the Mormon-national difference is smaller in countries where the history of church contact and tradition is brief. Thus, fertility is high in the U.S. where the LDS Church is centered, somewhat lower in Britain where the Church has maintained contact over 150 years, and lower yet in Japan where Mormon influence is very recent. In the less developed country where fertility is generally high, Mormon fertility is also high; but still lower than the national average (Mexico had an estimated total fertility rate of 4.3 in 1981).

Comparison of Mormon and National Fertility in Great Britain, Japan, and Mexico

Regression Model Predicting Children Ever Born for Mormon Women in Four Countries

Mormons in each country differ in other important respects. Those in the U.S. have completed more years of education than in Britain; Mexico has the lowest education (Japan’s education variable is not directly comparable). U.S. Mormons are most likely to conform to religious ideals of frequent attendance, endogamous marriage, and temple marriage. Britain takes an intermediate position, and Japanese and Mexicans are least likely to conform to these ideals. U.S. Mormons have also been baptized at a younger age and more of them have grown up in practicing Mormon families. Members in the other three countries are baptized, on average, at about age twenty-five and very few grow up in Mormon families. Thus, the religious context is very different in the U.S. than in the other three countries.

The total association between independent variables and fertility is assessed by correlation coefficients, [2] and the net effect is estimated by standardized and unstandardized regression coefficients. Demographic variables generally have the expected effects on fertility. Family size increases with marital duration and, with the exception of Mexico, couples who marry later have smaller families.

Contrary to tendencies in the general population, education has a positive relationship with fertility in Britain and Japan, and only a small negative relationship exists in the U.S. The positive effect of education arises probably because higher education is associated with greater orthodoxy (Albrecht and Heaton 1984; Heaton and Albrecht 1986), and greater orthodoxy implies having a larger family. Mexico provides a sharp contrast to other countries, in that education has a large negative impact on fertility. In fact, six additional years of education is associated with an average reduction by one child in average family size. In the Mexican context of rapid fertility decline, marked socioeconomic fertility differentials in the national population are mirrored among Mormons.

Acceptance of Mormon theology by securing a temple marriage is associated with an approximate .5 increase in family size in the U.S. and Japan. In Mexico, the effect is much smaller and not statistically significant. In Britain, the effect of temple marriage is actually negative, but not statistically significant. In each country, the lack of familial religious consensus as indicated by nonmembership of the husband is negatively associated with family size, and the coefficient is statistically significant in each country except the U.S. If we take the difference in the two extremes of temple marriage versus marriage to a nonmember husband (taking the difference between the unstandardized coefficients for temple marriage and husband not LDS), the differences are substantial: .66 children in the U.S., .88 in Japan, .67 in Mexico, and .35 in Britain. Although the pattern is not as strong in Britain, acceptance of the eternal family concept by husband and wife is associated with larger family size in each of the countries considered.

Wife’s church attendance is included as a measure of contact with a Mormon reference group. The effect of this variable on fertility is statistically significant in only one of the four countries, and the effect is actually negative in Japan. In the U.S., Britain, and Mexico, however, the magnitude of the effect implies that average family size for regular church attenders is .5 children greater than for nonattenders. Thus, the results are not as impressive for attendance as for marriage status, but there is a tendency for participating Mormons to have larger families.

The three indicators of socialization within a pronatalist context yield mixed results. In the U.S., coming from a larger family and baptism at an earlier age have a small association with having more children, but having LDS parents has virtually no effect on fertility. For Britain, the effects on number of siblings and age at baptism are similar to the U.S., but having LDS parents actually reduces family size. Due to the small British sample, however, none of these effects are statistically significant. Japan comes closest to the expected pattern where coming from a large family, early baptism, and having LDS parents are each associated with higher fertility. In Mexico, results are just the opposite of what was expected, but none of the coefficients are statistically significant. In sum, the socialization variables do not have consistent relationships with fertility. Even though the coefficients which are statistically significant do have effects in the expected direction, many coefficients are not statistically significant, and some have effects contrary to our expectations.

Although the results are not always consistent, some overall patterns do suggest ways in which Mormonism interacts with local cultures to influence fertility behavior. Pronatalism developed as part of the Mormon experience in the United States, and it is here that the most consistent patterns are found. In the U.S., Mormon fertility is well above the national average and religious variables have a substantial influence on fertility. Mormonism has been exported to the other three countries. Britain and Japan are industrialized countries which have achieved low fertility. In these two countries, Mormon fertility is somewhat above the national average and religious factors have less consistent effects on fertility. The Britain-Japan pattern suggests that people in these countries are only weakly influenced by Mormon pronatalism retaining fertility patterns that are not greatly different from the national cultures. In these two countries, Mormons’ values are probably a blend of national emphasis on replacement fertility and a religious emphasis on pronatalism.

A very different pattern is evident in Mexico. Mormon fertility falls below the national average, education has a strong negative impact on fertility, and the religious variables tend not to have positive influences on fertility. It is possible that joining the Mormon Church is associated with aspirations for upward mobility. The achievement orientation of the Church may override pronatalist values in this context. Thus, Mexican Mormons, especially the most educated ones, have families smaller than the national average. The results for Mexico suggest that in developing countries, other values associated with Mormonism may supersede pronatalism.


The LDS Church’s proselytizing effort has lead to substantial international growth. This successful proselytizing effort raises an important question: What behavioral and attitudinal changes accompany conversion to a new religion? This is particularly interesting when religions spread to new cultural contexts. In this paper we examine one type of behavior that has traditionally been associated with Mormonism, namely having large families. Family size provides an interesting test variable because it is not regulated by an explicit code of religious conduct. Rather, it is a cultural pattern which has emerged out of interpretation of theology incorporated into social structure.

An earlier analysis of Mormon fertility in the U.S. has shown that acceptance of a distinctive pronatalist ideology of marriage, contact with a Mormon reference group, and socialization within a pronatalist subculture each has an influence on family size. This study extends the analysis to consider three additional countries where the Mormon Church has a high conversion rate in recent years. Overall, the results of this analysis are consistent with the notion that religious involvement increases family size. Acceptance of a Mormon temple marriage, spousal congruence in religious affiliation, and frequency of church attendance are usually associated with higher fertility. Measures of socialization show less consistent results, but positive influence is evident in two of the four countries. Several of the coefficients for religious variables are even negative, but none of the negative results are statistically significant.

These results suggest that some behavior patterns not directly specified by precise codes of conduct are adopted by new converts in different sociocultural contexts. The cross-cultural similarities are weak enough, however, to imply substantial local autonomy in defining acceptable behavior which is not clearly specified by formal rules. The cross-national similarities suggest some degree of religious community in which members tend to respond to religious experience in a common fashion. The differences suggest that the national context continues to influence fertility so that religious affiliation is only one out of a complex set of factors that underlie fertility related behavior. In addition, national cultures appear to interact with Mormonism. Comparative patterns suggest that pronatalism is strongest in the U.S., that pronatalism is weakened but still present in other developed countries, but that other values may suppress pronatalism in developing countries.

Religious influence on individual behavior is complex. Various mechanisms of influence are at work and some types of people are more susceptible to influence than others. The process becomes more complex when conversion to a particular religion occurs in diverse cultural settings. Although this research leaves many questions unanswered, it does raise interesting points about the religious influence on fertility. There is a noticeable positive relationship between religious contact and fertility in each of the four countries, but the pattern and degree of influence varies dramatically. Pronatalism may be a persistent theme in Mormonism which is expressed cross-culturally, but the expression of that theme is different in each country.


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Albrecht, Stan L. and Tim B. Heaton. 1984. “Secularization, Higher Education, and Religiosity.” Review of Religious Research 26:43–58. Also in this volume.

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Heaton, Tim B. 1986. “How Does Religion Influence Fertility?: The Case of Mormons.” Journal for the Scientific Study of Religion 25:248–58.

Heaton, Tim B. and Stan Albrecht. 1986. “Religious Attendance, Socioeconomic Status, and Organizational Structure in the Mormon Church.” Unpublished manuscript.

Heaton, Tim B. and Kristen L. Goodman. 1985. “Religion and Family Formation.” Review of Religious Research 26:343–59.

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[1] Some women join the Mormon Church after the initiation of childbearing. Fewer than 20 percent, however, join after age thirty-five when childbearing is nearing completion. These data do not contain a fertility history which allows linking childbearing with baptism, but controlling age at baptism should reduce the confounding influence arising from late baptism.

[2] Path analysis is not appropriate since it is not possible to correctly specify causal ordering among the independent variables. This problem is not critical since the main purpose is to show the independent effects of each exogenous variable on fertility. The degree to which variables are correlated with fertility as a result of association with other variables in the model can be assessed by comparing zero-order correlations and standardized regression coefficients.