Having three or more children advances the cognitive decline of parents by 6.2 years when they get older. The effect is similar in men and women and has to do with the economic effort, the work impact and the stress involved in parenting.
Having three or more children has a negative effect on cognition during old age, a study conducted by the Columbia University Mailman School of Public Health (United States) and Paris-Dauphine University (France) has found.
The study even ensures that the negative effect of having three or more children on cognitive functioning is equivalent to 6.2 years of aging.
The results, published in the scientific journal Demography, also show that this effect is more pronounced in northern Europe, where higher fertility decreases financial resources, but does not increase the social resources available to families.
This study is the first to analyze the causal effect of high fertility on cognition in old age. Until this time, fertility had not received much attention as a potential predictor of cognition in old age, compared with other factors, such as education or occupation.
The researchers analyzed data from the Survey on Health, Aging and Retirement in Europe (SHARE) to see how having three or more children versus two causally affects cognition in late life. .
Based on advanced econometric methods capable of unraveling causality from simple associations, the data suggest that having three or more children versus two is associated with a worse cognition in later life. They also found that this effect is similar for men and women.
Fertility can affect late cognition through several pathways. Firstly, having one more child often entails a considerable economic cost, reduces family income and increases the probability of falling below the poverty line.
Under these conditions, the standard of living of all family members decreases and possibly causes economic worries and uncertainties, which could contribute to later cognitive deterioration.
Another way in which the number of children can affect cognition in old age has to do with the fact that having one more child implies a lower participation of women in the labor market, fewer hours worked and lower income.
As a third way, it highlights the fact that having children can be stressful, influence health risk behaviors and negatively affect the cognitive development of adults.
Parents with more children may experience more stress, have less time to relax and invest in cognitively stimulating leisure activities. This can imply sleep deprivation for the father or mother, with the consequent impact on health.
Nevertheless, not all are disadvantagesResearchers note that having children decreases the risk of social isolation among older people, which is a key risk factor for cognitive decline and dementia, and often increases the level of social interaction and support, which can be protective against cognitive impairment at advanced ages.
The researchers conclude that the decline in the proportion of Europeans who have three or more children may have positive implications for the cognitive health of the older population.
The researchers highlight that understanding the factors that contribute to optimal cognition in old age is essential to ensure successful aging at an individual and societal level, particularly in Europe, where family sizes have shrunk and populations are aging rapidly.
They add that cognitive health in old age is essential for maintaining independence and being socially active and productive, and that ensuring the cognitive health of the older population is also essential for extending working life and reducing health care costs and needs.
Does Childbearing Affect Cognitive Health in Later Life? Evidence From an Instrumental Variable Approach. Eric Bonsang; Vegard Skirbeck. Demography 9930490. DOI:https://doi.org/10.1215/00703370-9930490