A recent study published in The Journals of Gerontology: Series B sheds light on how early family dynamics and adult sibling relationships influence cognitive health in later life. The findings suggest that positive sibling interactions during childhood and frequent contact with siblings in adulthood are associated with better cognitive functioning in older adults.
Social relationships benefit cognitive health by stimulating mental processes, reducing stress, and encouraging healthy behaviors. While previous research has focused on relationships with spouses, parents, and children, less attention has been given to the role of siblings—who often have some of the longest-lasting relationships in a person’s life. Recognizing this gap, researchers sought to explore how childhood sibling interactions and adult sibling contact influence cognitive functioning in old age.
“The broader reasoning behind this study is that relationships are not built overnight. Especially in old age, family relationships reflect a history of countless years spent together,” explained study author Jooyoung Kong, an assistant professor at the Sandra Rosenbaum School of Social Work at the University of Wisconsin-Madison.
“My previous research has addressed this question through the lens of life course relationships with the original family of individuals who have experienced homes filled with various forms of violence and neglect. Specifically, I have examined how early experiences of violence and neglect affect adult children’s relationships with the parents who perpetrated the harm. The current research builds on my prior approach by exploring both positive and challenging childhood experiences within families and their impact on adult sibling relationships.”
The study utilized data from the Wisconsin Longitudinal Study, a long-term project that has followed over 10,000 high school graduates from 1957 and their siblings. This dataset, known for its breadth and depth, allowed researchers to examine sibling relationships and cognitive health over decades.
To ensure robust analysis, the researchers included sibling respondents who provided retrospective reports of childhood interactions and participated in multiple waves of data collection. They focused on data from four survey periods: 1994, 2005, 2011, and a newly collected dataset from 2020.
Childhood interactions were categorized into positive and negative domains. Positive interactions included acts of mutual support, such as helping and hugging, while negative interactions covered conflict-related behaviors like insults and physical aggression. Participants also reported adverse childhood experiences, including abuse, neglect, and household dysfunction.
The researchers evaluated adult sibling relationships based on two key dimensions: emotional closeness and contact frequency. Emotional closeness was assessed through a single question that asked participants to rate how close they felt to their sibling. Contact frequency was measured by asking how often they interacted with their sibling in the past year through in-person visits, phone calls, or letters.
Cognitive functioning in older adults was assessed using the Telephone Interview for Cognitive Status-modified, a widely used screening tool that evaluates memory, attention, reasoning, and other cognitive abilities. Scores on this test range from 0 to 50, with higher scores indicating better cognitive performance. This measure provided an overview of participants’ cognitive health in their early 80s.
The researchers found that participants who reported positive experiences with their siblings in childhood were more likely to maintain frequent contact with those siblings later in life. This finding highlights the enduring nature of early relationship patterns and the importance of nurturing positive bonds within the family.
Interestingly, negative sibling interactions during childhood did not show a clear impact on adult sibling relationships. The researchers suggest this may be because the intensity of the negative interactions measured was not severe enough to leave lasting scars or because strained relationships can improve over time.
Adverse childhood experiences, on the other hand, were associated with less frequent contact between siblings in adulthood. These findings align with existing research that suggests a challenging family environment can weaken sibling bonds.
“Negative interactions with siblings, such as verbal and physical aggression, do not seem to have lasting effects on these relationships in late adulthood,” Kong told PsyPost. “Rather than such direct negative interactions, challenging family environments—characterized by abuse, neglect, or mental health issues among household members—can lead to reduced solidarity among siblings. Overall, these findings suggest that a positive family environment, which fosters quality, affectionate interactions among family members, may have a significant long-term impact.”
Importantly, the frequency of contact between adult siblings emerged as a significant factor in cognitive health. Participants who maintained regular interactions with their siblings demonstrated better cognitive functioning in their 80s. This finding suggests that sibling contact may provide cognitive stimulation and emotional support, which can help protect against age-related cognitive decline.
Surprisingly, emotional closeness did not show a direct relationship with cognitive health. While closeness is often associated with psychological well-being, the researchers suggest that the cognitive benefits of sibling relationships may stem more from the frequency of interactions and the opportunities for engagement they provide.
The researchers found that the impact of childhood sibling interactions and adverse childhood experiences on cognitive health was largely indirect. Positive childhood interactions led to more frequent sibling contact in adulthood, which in turn was associated with better cognitive outcomes. Conversely, adverse childhood experiences reduced sibling contact, contributing to lower cognitive performance. These pathways highlight the cumulative effects of family relationships over the life course.
“The key takeaway from this research is that having quality sibling relationships during childhood—such as hugging, helping each other, and enjoying time together—can enhance older adults’ cognitive health through stronger cohesion with adult siblings,” Kong said. “Specifically, positive sibling relationships in childhood can contribute to increased contact and emotional closeness with siblings in adulthood, which can positively influence cognitive functioning later in life.
“Conversely, growing up in a troubled family environment—such as one characterized by abuse, neglect, or mental health problems—can adversely affect your contact and emotional closeness with your siblings, and these long-term associations may be linked to cognitive impairment in late adulthood.”
To account for potential confounding factors, the researchers controlled for demographic variables such as age, gender, marital status, health status, and education. They also included measures of family context, such as the number of siblings and childhood socioeconomic status. But as with all research, there are some limitations.
“One of the major limitations is that the study sample was mostly White and had completed at least a high school education with a relatively high socioeconomic status. Thus, our findings may not fully represent ethnic or racial minorities and those with low socioeconomic status,” Kong noted.
“The long-term goal of my research is to address the various experiences within families, with a particular focus on developing theories or hypotheses about the long-term impact of violence experienced within the family on life-course family relationships. For some, family is a lifelong source of support, while for others, it can be a lifelong struggle. I hope this line of research will contribute to enabling more people to engage with and address the challenges that are both experienced and ongoing within families.”
The study, “Life Course Associations of Sibling Relationships and Cognitive Functioning in Late Adulthood,” was authored by Jooyoung Kong, Sara M. Moorman, Gina Lee, and Michal Engelman.
