A study published in the journal Science has shown that experiences during early life can leave lasting marks on the body, affecting biological aging processes across multiple tissues.

The research was conducted by scientists from Arizona State University and Vanderbilt University in collaboration with partner research centers. The study focused on a unique population of rhesus macaques living in a natural environment on Cayo Santiago off the coast of Puerto Rico. Because these animals have been monitored since birth, researchers were able to link life experiences to molecular changes observed in adulthood.

Scientists analyzed 237 animals and examined samples from 12 different tissues, comparing them with DNA methylation data—an epigenetic mechanism that regulates gene activity and is widely used to estimate biological age through so-called “epigenetic clocks.”

The findings revealed that aging does not occur uniformly throughout the body. Different organs follow their own epigenetic aging trajectories: some tissues, such as the thymus and pituitary gland, showed more pronounced age-related changes, while others changed less dramatically. At the same time, a degree of coordination remained evident—animals that appeared biologically older in one tissue often exhibited accelerated aging in others as well.

A key discovery involved the impact of adverse early-life conditions, including maternal loss, low maternal social status, and living in highly crowded social groups. These factors were associated with epigenetic changes that appeared consistently across multiple tissues.

Researchers identified thousands of genomic sites where DNA methylation patterns were linked to early-life stress. Many of these sites also overlapped with age-related changes. However, the effects were not uniform: in some cases, the changes resembled accelerated aging, while in others they differed from typical aging patterns.

In other words, early-life stress does not simply “speed up aging.” Instead, it appears to reshape the organism’s epigenetic developmental trajectory, affecting different tissues in different ways.

The authors emphasize that these findings challenge the simplified view that a difficult childhood inevitably leads to uniform acceleration of biological aging. The effects depend on the type of tissue involved, the nature of the stress, and the developmental context.

The researchers also highlight the importance of studying multiple tissues. Most previous investigations relied primarily on blood samples, but the new findings suggest that blood provides only a partial picture of the aging process.

The use of rhesus macaques living in a complex social environment allowed scientists to connect individual life histories with molecular changes—something that is extremely difficult to achieve in human studies.

According to the authors, early life represents a critical period in shaping an individual’s biological aging profile. Experiences during this stage may leave long-lasting molecular signatures that influence health throughout life.