کودکان و رضایت زناشویی در یک نمونه غیر غربی: داشتن فرزند بیشتر رضایت زناشویی در میان مردم ایگبو نیجریه را افزایش می دهد

Previous research has demonstrated that having more children decreases marital satisfaction among parents. However, the universality of these findings is limited since the vast majority of the studies have been conducted in Western countries. In the present study, 374 people from the Igbo ethnic group (Nigeria) were assessed for levels of marital satisfaction and the number of children. In contrast to almost all previous findings, we found a positive relationship between the number of children and marital satisfaction among parents. Number of children was the strongest predictor of marital satisfaction even when compared to other variables like wealth and education. Our results suggest that the negative relationship between the number of children and marital satisfaction is not culturally universal and probably only characterizes developed, individualistic Western countries. We discuss our findings from a sociocultural and evolutionary perspective.

Formal marriage arrangements between men and women exist in every culture, and 90% of the world population marries at least once during their lifetime (Buss, 1985). Therefore, analyses of marriages and all the processes within such relationships, like marital satisfaction, are interesting from an evolutionary standpoint (e.g., Lucas et al., 2004, Lucas et al., 2008, Shackelford and Buss, 1997 and Shackelford and Buss, 2000; Wendorf, Lucas, Imamoğlu, Weisfeld, & Weisfeld, 2011). One of the significant determinants of marital satisfaction seems to be the number of children (see Twenge, Campbell, & Foster, 2003 for a review). A meta-analysis by Twenge et al. (2003) showed that the correlation between the number of children within a family and the parents’ marital satisfaction was negative. Gender, age of the youngest child, birth cohort, and the different measurements of marital satisfaction were not significant moderator variables in the correlation analysis. Additionally, parents had significantly lower marital satisfaction than nonparents. Several theoretical explanations have been put forth to explain the negative impact of parenthood and the number of children on marital satisfaction. Some of the most prominent are role conflict, restriction of freedom, sexual dissatisfaction, and financial cost models; but only the two former explanations find some support in the results of the meta-analysis (Twenge et al., 2003). However, the universality of such findings might be limited. Firstly, these results are surprising in the context of an evolutionary perspective. From this perspective, marital satisfaction is a psychological state regulated by the benefits and costs of marriage to a particular person (Shackelford & Buss, 2000). It is intriguing why very important profits—higher reproductive success or a lower possibility of family abandonment by men (Betzig, 1989)—do not have a positive influence on marital satisfaction. One explanation of such findings is that declines in marital satisfaction evolved as a biological function to focus parent's attention on children (Wendorf et al., 2011)—any decline in marital satisfaction may be transferred to a rise in satisfaction derived from one's children. This hypothesis was supported by results showing that married couples with children are no less happy “in general” than couples without children (Houseknecht, 1979 and Kohler et al., 2005). Most psychological studies trying to depict human universals are in fact only extrapolations of a single social group (Western, developed, educated, etc.; see Henrich, Heine, & Norenzayan, 2010). As such, most samples analyzed by Twenge et al. (2003) were from Western countries. All of these countries are indeed developed and have relatively high status and well-developed social security systems. Additionally, they are all highly individualistic (Hofstede, 2001) cultures. There are several reasons why those elements might have influenced the obtained results at the population level. Contrary to individualistic cultures, intragroup relationships in collectivistic countries are characterized by mutual help, loyalty, and cooperation (Hofstede, 2001). This means that, in families, parents may count on the help of others (namely, relatives) for the upbringing of their children. At the same time, in collectivistic cultures, multigenerational families often live together; and children take care of their siblings or elderly relatives (Rosenthal, 1999). It might be hypothesized that collectivistic cultures not only “support” the institution of marriage but also might decrease the impact of problems related to having additional children and the negative influence they could have on marital satisfaction. Recent studies have partially confirmed the hypothesis about the differential impact of parenthood on marriage in collectivistic cultures. Dillon and Beechler (2010) conducted a meta-analysis that aggregated the findings on the impact of children on marital satisfaction in 15 collectivistic cultures. Although they found a negative correlation between the number of children and marital satisfaction, it was lower than the findings of Twenge et al. (2003). Another variable that could possibly influence the relationship between parenthood and marital satisfaction not considered so far is the availability of social care and pensions. From the evolutionary point of view, social pensions are a relatively modern “invention”; additionally, this system is more popularized in developed countries (Barrientos, 1998). Data collected in many nondeveloped populations showed that old-age security motives are an important motive for fertility, particularly when relevant parents are both uncertain about their ability to be self-supporting in old age and dubious that there are other more reliable means of such support than their child (see Nugent, 1985 for a review). In many developing African countries, only a small percentage of society has access to free social benefits or any type of pension (Stewart & Yermo, 2009). We hypothesize that, in such situations (which are closer to the life conditions of our ancestors), family and children are probably the substitutes of social care for the elderly, which should modify the relationship between the number of children and marital satisfaction. The aim of our study was to investigate the relationship between the number of children and marital satisfaction in a non-Western society: Nigeria. Nigerians live in a more traditional society (in comparison with Western countries) and have higher rates of fertility. Additionally, Nigeria is a collectivistic (Hofstede, 2001), developing country with poor social security for the elderly (in comparison to the United States or European countries) (Stewart & Yermo, 2009). What is more, in Nigerian society, marriage and children are perceived as extremely important (Muomah, 2010). Therefore, we might presume that having more children would positively influence parents’ marital satisfaction in this particular area of the world.