Adult friendships can triumph over childhood trauma, even in baboons

Newswise — DURHAM, N.C. -- DURHAM, N.C. -- Extensive studies reveal that encountering distressing events during childhood -- such as having an inebriated guardian or being raised in an unstable household -- increases the likelihood of compromised well-being and longevity in the future.

But accumulating proof implies that cultivating robust social bonds can aid in alleviating these consequences. Moreover, this applies not only to humans but also to our primate counterparts.

Utilizing a dataset spanning 36 years, a recent investigation involving approximately 200 baboons in southern Kenya reveals that early-life adversity can significantly reduce their lifespan. However, the study also highlights that establishing resilient social connections with fellow baboons during adulthood can assist in recuperating those lost years.

"Senior author Susan Alberts, professor of biology and evolutionary anthropology at Duke University, expressed the sentiment by citing the King James Apocrypha, stating that 'a faithful friend is the medicine of life.' "

Baboons who faced challenging childhoods managed to regain a substantial two-year increase in life expectancy by establishing strong friendships.

The findings appear May 17 in the journal Science Advances.

Research consistently demonstrates that individuals who undergo a higher number of adverse experiences during their upbringing, such as abuse, neglect, or having a parent with a mental illness, are at an increased risk of premature mortality. However, unraveling the precise mechanisms linking these experiences and their consequences has proven to be a more challenging task.

Although the negative consequences of a challenging upbringing have been extensively documented, identifying the precise underlying mechanisms has posed a greater challenge, as highlighted by Alberts.

One of the limitations observed in previous research was the reliance on individuals' self-reported memories of their past, which can be subjective and lack precision.

Alberts explained that this is where long-term studies on wild primates, who share over 90% of our DNA, play a crucial role. Since 1971, researchers have diligently tracked individual baboons near Amboseli National Park in Kenya, recording their social interactions and monitoring their well-being throughout their lifetimes as part of the Amboseli Baboon Research Project.

In the new study, the researchers aimed to uncover the mechanism through which early-life adversity ultimately contributes to premature death, even after a significant time has passed.

One hypothesis suggests that individuals who experience trauma in childhood often struggle with building stable relationships in adulthood, leading to a lack of social support that can shorten their lifespan. However, the recent findings present a different perspective on the causal pathway observed in baboons, offering a glimmer of hope.

In the study, the researchers examined the impact of early-life experiences and adult social connections on long-term survival by studying a group of 199 female baboons closely monitored at Amboseli between 1983 and 2019.

While baboons don't grow up in broken or dysfunctional homes as humans do, they still face their fair share of challenges. To assess early adversity, the researchers examined six potential sources of hardship for each female baboon. These included having a low-ranking or socially isolated mother, experiencing the death of the mother before reaching maturity, being born during a drought year, being born into a large group, or having a sibling close in age, which could lead to increased competition for resources or maternal attention.

The findings indicate that stressful experiences are prevalent for baboons raised in the semi-arid and unpredictable environment of Amboseli. Among the baboons included in the study, a significant 75% of them endured at least one form of stressor, while 33% experienced two or more stressors during their upbringing.

The analyses conducted in the study supported previous findings that demonstrated a correlation between a higher tally of hardships during early life and a shorter lifespan in female baboons. However, the researchers discovered that this connection was not solely due to the fact that baboons who experienced more upheaval early in life tended to be more socially isolated as adults, despite the observed social isolation, as explained by Alberts.

Instead, the researchers were able to demonstrate that 90% of the decline in survival could be attributed to the direct effects of early adversity, independent of the weakened social bonds that baboons naturally experience in adulthood. This suggests that the adverse experiences during early life have a significant impact on longevity, primarily through factors other than compromised social connections in adulthood.

The cumulative effects of early hardships were notable, with each additional adversity translating to a loss of approximately 1.4 years of life, regardless of the strength or weakness of their bonds with other baboons. For instance, baboons who experienced four adverse events during their upbringing passed away nearly 5.6 years earlier than those who faced none of these hardships. Considering that the average lifespan of a female baboon is around 18 years, this represents a significant decrease in longevity.

However, it is important to note that having an unfortunate start in life does not necessarily condemn baboons to a life cut short.

"Females who have challenging early lives are not destined for an unfavorable outcome," emphasized first author Elizabeth Lange, assistant professor at SUNY Oswego.

On the contrary, the researchers made an additional significant discovery. They found that baboons who developed stronger social bonds, measured by the frequency of grooming with their closest companions, managed to extend their lives by an impressive 2.2 years, regardless of the adversities they had experienced during their early years.

Baboons who experienced the loss of their mothers before reaching maturity but subsequently formed strong friendships in adulthood exhibited the greatest ability to recover and mitigate the negative effects of early-life adversity.

Alberts noted that the converse is also true: strong social bonds have the potential to alleviate the impact of early-life adversity, while weak social bonds can intensify its effects. In other words, the presence of supportive and nurturing social connections can serve as a protective factor against the adverse consequences of a challenging upbringing.

While the generalizability of these findings to humans is yet to be determined, if applicable, the results imply that early intervention is not the sole effective approach for mitigating the effects of childhood trauma. The study suggests that cultivating strong social bonds in adulthood may serve as an additional avenue for overcoming the long-term impacts of early-life adversity.

"We discovered that both early-life adversity and adult social interactions have independent effects on survival," stated Lange. "This implies that interventions targeting various stages of life could potentially enhance survival outcomes."

In summary, emphasizing the importance of adults and their capacity to establish and sustain meaningful relationships can also be beneficial. This highlights the potential value of focusing on adult individuals in interventions aimed at addressing the consequences of early-life adversity.

Alberts emphasized the significance of forming social connections by stating, "If you have experienced early-life adversity, it is crucial to prioritize building friendships. Regardless of the circumstances, making an effort to establish strong social bonds can be highly beneficial."

This research was supported grants from the National Institutes of Health (R01AG053308, P01AG031719, R01AG053330, R01AG071684, R01HD088558 and R01AG075914) and from the National Science Foundation (1456832)

CITATION: "Early Life Adversity and Adult Social Relationships Have Independent Effects on Survival in a Wild Primate," Elizabeth C. Lange, Shuxi Zeng, Fernando A. Campos, Fan Li, Jenny Tung, Elizabeth A. Archie, and Susan C. Alberts. Science Advances, May 17, 2023. DOI: 10.1126/sciadv.ade7172.

# # #