Stable Souls Who Marry, Wild Egotists Who Divorce

At a time when national marriage rates are astonishingly low and national divorce rates remain distressingly high, Americans might learn something from a new Finnish study about the personal characteristics of those young people most likely to make enduring marriages and about the contrasting personal characteristics of those most likely to divorce. Conducted by a large team of researchers from Finland’s premier univer-sities and public-health institutions, this study limns a clear distinction in temperaments separating those who marry and stay married and those who turn their marriage into a reason for employing a divorce lawyer.

To categorize “temperament clusters” in the Finnish population, the researchers pored over data collected from 3,761 individuals included in the Northern Finland Birth Cohort 1966 and from 2,097 individu-als participating in the Cardiovascular Risk in Young Finns study. More particularly, the researchers examined data obtained from use of a Temperament and Character Inventory (TCI), which measures “indi-vidual differences along four main temperament dimensions: novelty seeking (NS), harm avoidance (HA), reward dependence (RD) and persistence (P).” “Novelty Seeking (NS),” the Finnish scholars explain, means “a tendency to respond with intense excitement to novel stimuli.” “Harm Avoidance (HA)” translates as “a tendency to respond intensively to signals of aversive stimuli, thereby inhibiting behavior.” “Reward Dependence (RD)” manifests itself as “a tendency to respond intensely to signals of reward, especially social rewards.” And “Persistence (P)” shows up, naturally enough, as “a tendency to persevere in behaviors that have been associated with reward or relief from punishment.”

Although four “temperament clusters” emerge in the researchers’ data, only two of these clusters correlate with distinctive marital patterns. The individuals that the researchers categorize as “Cluster I” tempera -ments are distinctive in a number of ways. These are individuals who are notably “stable, persistent and not very impulsive.” They enjoy “a high quality of life” and stand out for their high “working capacity” and their “relatively high level of education.” Their personal habits are especially healthy: “they brush their teeth, do not drink very much alcohol, and only rarely smoke.” Psychological measures indicate that they are dis-tinctively free from “psychosis proneness and symptoms for depression and anxiety.” Overall, they “possess features enabling mental stability and psychological adaptability, leading to practice of healthy life habits, stable life features, and decreased risk for mental disorders.” Oh, and one more thing: “Both females and males [in this cluster] are more often married than individuals from the other clusters.”

A very different temperament and marital trajectory shows up among those whom the researchers classify as “Temperament II.” The researchers characterize the men and women in this temperament cluster as “outgoing, energetic people who tend to be impulsive.” Survey data apparently indicates that these men and women are “like individuals from Cluster I, [in that] they have a high quality of life and self-reported working capacity.” Men and women in this cluster actually have “the highest level of education” measured in the researchers’ assessment of the four temperament clusters, and “their annual income is on average higher than other clusters.” They report “the best physical functional capacity” of individuals in the four temperament clusters, and they also appear relatively free from psychological illness—except, revealingly, from “hypomania,” a type of bipolar disorder characterized by wild flamboyance, hyper-kineticism, and irritability. Cluster II Individuals are also notably prone to smoking and drinking—and narcissistic lying. The researchers detect “a tendency of Cluster II individuals to embellish reality,” so creating a “need for caution when interpreting [their] self-reports of positive lifestyle and health-related variables.” And the kicker: “Divorces are more common” among Cluster II individuals than among peers belonging to the other three clusters.

The authors of the new study lay no special emphasis on the marital implications of their findings. Nor do they suggest that it might be possible to change individuals’ temperaments in ways that would foster lasting marriages. Still, readers of their study may wonder just whether our cultural and political elite have not become all too dismissive of the stable souls who keep their marriages together, and all too accommodating of the rich but often mendacious hypomaniacs who fill the divorce courts.

(Jaana Wessman et al., “Temperament Clusters in a Normal Population: Implications for Health and Disease,” PLoS One 7.7 [July 2012]: e33088.)