The Developing Developmental Biology of Childhood Adversity




Macaque monkey

Research over the last century has shown — unsurprisingly — that social hardships in early life can cause enduring health problems. A common example is poor nutrition, clearly a link between childhood poverty and adult illness. A related, heartening puzzle: how do some kids manage to thrive despite such socioeconomic disadvantages?

Cutting-edge studies in animal biology are shedding new light on a major reason why. That is, the development of biology and behavior is driven by gene-environment interactions. The upshot is that individuals are not affected equally by tough conditions. These individual differences arise from the interplay between an organism’s inherited traits and its surroundings. The classic notion of “nature versus nurture” is thus rendered obsolete.

The tricky part is how to go about understanding the role of individual variation in organisms’ responses to their environments. These dynamics are notoriously difficult to study and predict. Variation in numerous genes, operating in hyper-diverse environments, leads to complex interactions. Teasing apart the relationships demands sophisticated analyses, including experimental approaches not possible in human research. In this way, studies of other species are identifying mechanisms for the health impacts of early social stress.

For example, macaque monkeys reared without their mothers develop emotional abnormalities, such as poor social skills and aggression. Recent experiments show that the response to those adverse conditions depends on individual variation within a gene. The gene is linked to production of a protein involved in brain function, and in mediating responses to stress, anxiety and depression.

Studies of simple model animals take this work further, enabling actual gene manipulation. Fruit fly experiments show how chronic food deprivation at the larval stage interacts with natural variation in a gene that controls foraging. The early adversity then influences adult exploratory behavior. This willingness to investigate is essential for finding food — in mammals it is also critical for development of independence and mate selection. The poor nutrition in flies also affects eventual reproductive output, the ultimate index of a stressor’s impact.

Collectively, such studies show that some genotypes may be more sensitive to environmental conditions than others. That means individuals can experience different behavior and health outcomes in response to the same conditions.

This research into the “developmental biology of social adversity” is an important advance in studying the health impact of early life conditions. Conventional approaches tend to miss the point that many interacting factors underlie most health problems. Important questions in this emerging field include how the strength, timing, and duration of early life adversity influence development, and how interventions might alter health outcomes.

References

Bardo MT (2010). Novelty, Pages 471–476 in Encyclopedia of Behavioral Neuroscience. Academic Press. doi: 10.1016/B978-0-08-045396-5.00168-8

Boyce WT, Sokolowski MB, & Robinson GE (2012). Toward a new biology of social adversity. Proceedings of the National Academy of Sciences of the United States of America, 109 Suppl 2, 17143-8 PMID: 23045689

Burns JG, Svetec N, Rowe L, Mery F, Dolan MJ, Boyce WT, & Sokolowski MB (2012). Gene-environment interplay in Drosophila melanogaster: chronic food deprivation in early life affects adult exploratory and fitness traits. Proceedings of the National Academy of Sciences of the United States of America, 109 Suppl 2, 17239-44 PMID: 23045644

Cirulli F, Reif A, Herterich S, Lesch KP, Berry A, Francia N, Aloe L, Barr CS, Suomi SJ, & Alleva E (2011). A novel BDNF polymorphism affects plasma protein levels in interaction with early adversity in rhesus macaques. Psychoneuroendocrinology, 36 (3), 372-9 PMID: 21145664

Image via stoonn / Shutterstock.

  • Exactly how much did Harvard spend funding this research and who paid for it? Does this study advance knowedge one iota? Instead of funding studies of this sort, perhaps one day we will fund solutions.

  • Jai Catalano

    I wonder how this affects adopted children. If a child is left in an orphanage how does the intervention (adoption) alter behavior during various stages of a child’s life? For example if a child is adopted at 3 years old vs 6. I am sure it makes a huge difference.

  • Catherine

    If like the article stated,different people have different reaction although they live in same environment condition.How could we explain about the identical twins’s behaviour if they put into same situation?

  • B.A. Bond

    Perhaps Owen hasn’t overcome his childhood adversity. Hopefully someone will fund a study which will enable people to overcome negativity one iota at a time.

    Enjoyed the article.

  • Erin

    I think this is what most parents need to know. Every child reacts to a different environment or situation. This is also where they adapt their attitude, and their skills. Developmental tasks of every child should be met or else, they would acquire such mannerisms when they reach their middle school age or adolescent age, not just that, they will be even have self esteem or self confidence issues and etc. So, parents must always be there for their child ensuring that they will be guiding them all throughout their childhood days.

  • David

    I hope they will be able to have further studies especially on how to solve this problem. A better understanding of how an individual reacts to the environment and the factors that make them react differently despite living in the same house. This study would surely improve parenting and help nourish children.

  • I’m so happy by visit this site that I’ve already bookmark this site and I will come back again . Thank for your great post.
    For Angel Card Readings please click here
    and you will be helpful by our service like as Angel Card Readings , Removal of Curses, Spells and Evil etc.
    Thanks

  • Parents should learn a lot from this article. Responsible parenthood can produce healthy children in the future and it will have long lasting positive effect on them. If the children are nurtured well then expect for a good physical and mental health when he/she becomes an adult.

    Want to learn about prostate health? Check this out

Kara Lefevre, PhD, MSc

Kara Lefevre, PhD, MSc, is a professional environmental biologist, educator, and science writer. She holds a PhD in Ecology and Evolutionary Biology from the University of Toronto and a MSc in Biology from Queen's University. She has combined her interests in biology and travel by studying birds in remote island locations around the world.
See All Posts By The Author

Do not miss out ever again. Subscribe to get our newsletter delivered to your inbox a few times a month.