Social and Psychological Bases of Homogamy for Common Psychiatric Disorders.

Sociologists and psychologists have long been interested in the origins of assortative mating for social and psychological characteristics. Sociologists have focused on the influence of social structure on the choice of a marital partner. Geographic propinquity, race, age, and social class have all been shown to affect the relative attractiveness of potential partners and to constrain the "field of eligibles" from which persons select partners (e.g., Burgess & Wallin, 1943; Hollingshead, 1950). In contrast, psychologists have focused on attraction based on psychological characteristics such as personality (e.g., Buss, 1984; Pond, Ryle, & Hamilton, 1963) and psychiatric disorders (e.g., Dunner, Fleiss, Addonizio, & Fieve, 1976; Gershon, Dunner, Sturt, & Goodwin, 1973; Gregory, 1959; Jacob & Bremer, 1986; Kreitman, 1962; Merikangas, 1982; Nielsen, 1964). These two literatures have developed independently with little communication occurring between them. This article evaluates the contribution of social experiences to homogamy for anxiety disorders, major depression, and alcohol or drug dependence. Early studies of homogamy for psychiatric disorders acknowledged the potential influence of social factors like shared life experiences but provided little empirical evidence with which to confirm or disconfirm that influence (e.g., Gregory, 1959; Kreitman, 1962). More recent studies have moved away from social explanations to propose explanations that rely almost exclusively on theories of interpersonal attraction (e.g., Dunner et al., 1976; Merikangas, 1982). Given clear evidence that social and psychological experiences are related (e.g., House, 1981), analyses of psychiatric homogamy would benefit from an explicit consideration of social experiences. I estimate the level of homogamy within and across these disorders, and evaluate five prevailing explanations for the observed homogamy: primary assortative mating, secondary assortative mating, similarity due to shared experiences, increasing similarity through interaction, and responses to the stress of a partner's disorder. To varying degrees, these alternatives link social and psychological experiences as they influence psychiatric similarity between spouses. PREVIOUS RESEARCH Homogamy appears to be the rule for depressive disorders, alcoholism, and phobic disorders, as it is for major social characteristics (see Merikangas, 1982, for a review). Despite decades of relevant research, however, even that basic conclusion can be questioned. Almost all existing studies of psychiatric homogamy used clinical samples, which means that estimated levels of homogamy may not generalize to the untreated population. Levels of homogamy may be higher in clinical samples than in community samples if psychiatrically ill spouses facilitate each other's entry into treatment (Gregory, 1959; Kreitman, 1968). Alternatively, levels of homogamy may be lower in clinical samples if members of homogamous couples recover more quickly, perhaps because their shared experiences create mutual empathy and support (McLeod, 1994). Regardless of which type of bias occurs, if treatment seeking and recovery are influenced by the presence of a psychiatrically ill spouse, levels of homogamy from clinical samples may be inaccurate. Thus, the first goal of this analysis is to estimate the level of homogamy for common psychiatric disorders in a community sample of married couples. Assuming that homogamy exists for psychiatric disorders, the question that follows concerns the origin of that homogamy. Two main classes of explanations have been proposed: assortative mating and experiences subsequent to the marriage. Within each broad class of explanation, several variants exist. Assortative mating explanations focus on nonrandom selection of marital partners. Two types of assortative mating may occur. The first, primary assortative mating, is defined as nonrandom selection of marital partners based on the trait of interest. …