The Scars of Cruelty: Biological Effects of Parent-Child Separation

“Cruelty is surely the very worst of human sins. To fight cruelty, in any shape or form – whether it be towards other human beings or non-human beings – brings us into direct conflict with that unfortunate streak of inhumanity that lurks in all of us.” – Jane Goodall (2010: 306)

An infant cries as U.S. Border Patrol agents process a group of immigrants in Granjeno, Texas, June 2014. (Photo: Jerry Lara, Staff / San Antonio Express-News).


Earlier this month Attorney General Jeff Sessions gave a public speech in Scottsdale, Arizona where he announced that the departments of Justice and Homeland Security would separate all children from adults who crossed the U.S. border, regardless of whether they did so illegally or were claiming asylum. Sessions framed this somewhat ambiguously by referring to the “smuggling” of children. Yet it was also clear that he meant for this to be a deterrent to parents, as they would have their own children taken from them:

“If you are smuggling a child, then we will prosecute you and that child will be separated from you as required by law. If you don’t want your child to be separated, then don’t bring them across the border illegally.”

Several advocacy groups immediately denounced the policy as cruel and inhumane, including Amnesty International, the ACLU, and the Women’s Refugee Commission. The group Kids in Need of Defense stated that in addition to being cruel, the policy would make it more difficult to process cases for families who are seeking asylum from violence, since it is harder to get information from parents and children who are kept in separate places.


The Situation in Central America

The need to process asylum cases efficiently is especially relevant today. Last year saw 294,000 people from Central America (primarily El Salvador, Honduras, and Guatemala) claim asylum or refugee status in other countries as they fled from rising levels of violence. According to UNHCR , that number was sixteen times higher than it was in 2011. In addition, roughly 714,500 people in Guatemala, Honduras and El Salvador remained internally displaced in June 2017. That is, they were forced from their homes but had not crossed an international border. Data from the Igarapé Institute in Brazil show that homicide rates in Central America are among the highest in the world , with levels of violence that rival war-torn countries.

Furthermore, the number of Central Americans seeking asylum had also increased in Belize, Mexico, Panama, and Costa Rica, showing that while some cases may be economic migrants looking for work in the U.S., many are simply desperate people fleeing organized gang violence, human trafficking, extortion, and corrupt police/ judicial systems. And some may choose to leave based on a combination of factors. Regardless of the cause, it cannot be an easy decision to make, particularly for parents.

UNHCR’s Francesca Fontanini said that short-term solutions, (which would include things like deportations and parent-child separation) were not likely to ameliorate the situation. In fact, they could even make things worse. According to Robert Muggah, one factor exacerbating the situation in Central America is the sheer scale of deportations from the U.S., in particular people with criminal records:

“Between 2013 and 2015, the US government authorised the deportation of more than 300,000 Hondurans, Guatemalans and Salvadorans with criminal records, many of them children of refugees from the 1970s and 1980s. Another 550,000 Mexicans were also deported over the same period.

The return of so many people, many of them convicted felons, coincided with a sharp uptick in criminal violence in Central America and Mexico. The policy of deporting Latin Americans was actually expanded during the Obama administration. For years the returnees have strained local criminal justice and penal systems to breaking point – overcrowded prisons are even referred to as “crime colleges” or “finishing schools for crime.”

Fontanini added that “we need the states who are receiving these people to invest in longer-term solutions.” What that would entail, she did not say. But it is clear that instability perpetuates itself, and that this does not stay neatly contained within national borders. It is also clear that innocent Central Americans are being crushed between organized crime in their home countries and a sense of indifference or hostility from neighboring nations. President Trump even went so far as to say about “unaccompanied alien minors” (i.e., children), “they look so innocent. They’re not innocent.” The implication was that organized criminals, including members of the notorious gang MS-13, were infiltrating across the border with some pretending to be asylum seekers.

The statistics show that this does occur, though rates appear to be low. According to The New York Times, 240,000 unaccompanied minors entered the US between 2012 and 2017. Only fifty-six of those were linked to MS-13. There is a moral imperative to avoid painting innocent people as the very perpetrators of violence from whom they are fleeing (the same could be said about refugees from Syria and other war-torn countries, who are often conflated with terrorists). Furthermore, Trump’s claim was contradicted by his Chief of Staff, John Kelly, who indicated that the primary reason for preventing immigration from Central America was more about assimilation than crime.

“Let me step back and tell you that the vast majority of the people that move illegally into the United States are not bad people. They’re not criminals. They’re not MS-13. … But they’re also not people that would easily assimilate into the United States, into our modern society. They’re overwhelmingly rural people. In the countries they come from, fourth-, fifth-, sixth-grade educations are kind of the norm. They don’t speak English; obviously that’s a big thing. … They don’t integrate well; they don’t have skills. They’re not bad people. They’re coming here for a reason. And I sympathize with the reason. But the laws are the laws. … The big point is they elected to come illegally into the United States, and this is a technique that no one hopes will be used extensively or for very long.”


“Cruelty is the Point”  

When John Kelly was asked about whether he thought it was cruel and heartless to take a mother away from her children, he replied , “I wouldn’t put it quite that way. The children will be taken care of — put into foster care or whatever.” Kelly is an alumnus of UMass Boston, where I have taught since 2003. I think he is an intelligent person, but this seems to be feigned ignorance. All he would have to do is take a moment to imagine a young child being separated from their parents — perhaps imagining himself as a boy in Brighton, or thinking of his own children being taken away when they were young. I’m sure he would quickly conclude that this would be a difficult experience. Again contradicting each other, President Trump acknowledged this when he tweeted that the policy of separation was “horrible,” though he neglected to mention that he was reportedly dismayed that some subordinates “were resisting his direction that parents be separated from their children.”

Kelly seemed to be saying that children would be cared for and not put in any physical danger, though that does not always seem to be the case. The Department of Health and Human Services admitted that it could not account for 1,475 migrant children who had been placed with sponsors. During the Obama administration, some unaccompanied children who were in foster care ended up in the hands of human traffickers , indicating that policies and procedures that were “inadequate to protect the children in the agency’s care.” Also, the ACLU reported that unaccompanied immigrant children detained by U.S. Customs and Border Protection faced “pervasive abuse and neglect,” as well as denial of basic health care and being allowed to stand or move freely for days. For its part, the CBP denied the allegations (though there were 30,000 pages of them). Deportations during the Obama administration also led to thousands of children being separated from their parents as well, and many children have arrived at the border unaccompanied by an adult, so children being apart from their parents is not entirely new. What is new is the deliberate separation by U.S. officials at the border, creating a problem where there was none.

Even without being outright abused, neglected, or lost, there is good reason to believe that parent-child separation (including infants as young as a year old) is inherently harmful, and could reasonably be called cruel. Matt Yglesias wrote that “The reason we know it’s cruel — and the reason we know Kelly knows it’s cruel — is that the cruelty is the point.” After all, that is why separation is meant to be a deterrent. A year ago, when Kelly first publicly floated the idea of parent-child separation, he acknowledged that deterrence was the objective. Would any parent who loved their kids want to see their child taken from them? As an analogy, the Russian-American journalist Masha Gessen referred to the many recent examples of Russian police detaining children who protested against Vladimir Putin as a form of “hostage-taking:”

“Hostage-taking is an instrument of terror. Capturing family members, especially children, is a tried-and-true instrument of totalitarian terror. Memoirs of Stalinist terror are full of stories of strong men and women disintegrating when their loved ones are threatened: this is the moment when a person will confess to anything.”


The Biological Scars of Separation

“Five years old. What kind of scars are we creating? The child has to be asking, where’s my mom? And that kid has to be scared. I can’t even fathom.”   – Public defender Miguel “Andy” Nogueras


Few could deny that parental-child separation inflicts suffering. A year ago, when rumors of the separation policy were leaked, the American Academy of Pediatrics released a statement against it, noting that it would cause additional pain for children:

“Pediatricians work to keep families together in times of strife because we know that in any time of anxiety and stress, children need to be with their parents, family members and caregivers. Children are not just little adults and they need loved ones to comfort and reassure them.

“Federal authorities must exercise caution to ensure that the emotional and physical stress children experience as they seek refuge in the United States is not exacerbated by the additional trauma of being separated from their siblings, parents or other relatives and caregivers. Proposals to separate children from their families as a tool of law enforcement to deter immigration are harsh and counterproductive.  We urge policymakers to always be mindful that these are vulnerable, scared children.”

There is some evidence that these traumatic experiences can have long-term effects. Viet Thanh Nguyen, a professor at the University of Southern California, described his own experience as a 4 year-old child who was separated from his family at the end of the Vietnam War. Nguyen wrote that “Memory for me begins here, howling with fear and pain as I was taken from my mother, too young to understand that I would be returned to her in a few months.” He added that: 

“being separated from my parents hurt enough for me to remember it vividly more than 40 years later. I can easily imagine the kind of damage a prolonged removal, under much more adverse circumstances, would do to a child. Or to a parent, since I am now the father of a 4-year-old myself. I say I can imagine it, but the pain of losing my son is actually unimaginable.”

Like Nguyen, I don’t think I can fully comprehend how hard it would be to have a child taken from me. On an emotional level, I think the closest word to describe how I would feel would probably be “anguish” for my child’s pain, and probably “anger” toward the people who caused it. On an intellectual level, I think most of us would probably feel this way, and I think I know why. Forgive me, but I cannot help but to view all of this at least partly from the perspective of a biological anthropologist.

Perhaps this is going back one step too far, but I think it’s important to remember that some of the hallmarks of being human are (1) our obligatory sociality, and (2) the intensity of the parent-child bond. Connections are essential, as none of us is an island. For example, large epidemiological studies show that strong social relationships are a better predictor of longevity among the elderly than whether one is obese or exercises regularly (Holt-Lunstad et al. 2010). Similar patterns have also been found in baboons, where females who had stronger and more stable social bonds lived longer (Silk et al. 2010).

This makes sense, as nearly all primate species are group-living and intensely social. The neurobiologist Matt Lieberman argued that we are “wired to connect” socially because this carried evolutionary benefits that enhanced our ancestors’ chances for survival, and that this goes deep into our primate and mammalian heritage. However, there are also costs to being so heavily invested in others, such as the potential for loneliness, isolation, neglect, ostracization, bullying, rejection, and loss. Furthermore, social pain is real and overlaps neurologically with physical pain:

“Throughout our lives, we are destined to experience different forms of social rejection and loss… Such breakups often feel unbearable, and they can dramatically alter how we view ourselves and our lives for a long time after. Our Faustian evolutionary bargain allows us humans to develop slowly out of the womb, to adapt to specific cultures and environments, and to grow the most encephalized brains on the planet. But it requires us to pay for it with the possibility of pain, real pain, every time we connect with another human being who has the power to leave us or withhold love. Evolution made its bet that suffering was an acceptable price to pay for all the rewards of being human.”  (Lieberman, 2013: 69-70)

If such connections are important for older primates – including humans – with a lifetime of experience behind them, then they are even more important for the young and vulnerable. Primates tend to have singleton births (one at a time) instead of litters of offspring, and they are altricial at birth (highly dependent), requiring years of care. As mammals they require nourishment from their mother’s breastmilk. And they also require a feeling of security, as Harry Harlow famously demonstrated decades ago. In Harlow’s experiments with infant rhesus macaques (monkeys) they were given a choice of surrogate “mothers” – one made of wire that provided milk, the other covered in soft terry cloth but provided no milk. Infants spent up to eighteen hours a day with the terry cloth surrogate mother, an indication that for young monkeys attachment and security were equally as important as nutrition, if not more so.  

Harlow also completely isolated infant monkeys for lengthy durations, some for 3, 6, or 12 months (Harlow et al 1965). Among the eighteen infants, they showed an array of behavioral problems, including anorexia, self-clutching, aggression, fear, and stunted sexual development. The ones who were isolated the longest fared the worst; Harlow et al noted that “12 months of isolation almost obliterated the animals socially” (p. 94). Isolated monkeys did not learn as well as controls, but due to the small sample size this was not statistically significant. They noted that “we can, however, state with confidence that the ‘intellectual mind’ is far less crippled than the ‘social mind’ by prolonged total social deprivation if adequate experience is provided subsequently” (p. 95).

Of course, children are not monkeys, or any other type of animal. But there are lessons we can draw from other species. The Central American children separated from their parents will not be completely isolated as Harlow’s monkeys were. Nor will they be isolated for months. Still, there is evidence that even brief maternal separation in young mammals can be detrimental. In a recent study, Sarine Janetsian-Fritz and colleagues removed 9-day old rats from their mothers for 24 hours (Janetsian-Fritz et al 2018). They found that even this brief, but stressful, separation had long-lasting behavioral and physical effects, including mild memory impairment, less communication between brain regions, suggesting “increased probability of developing psychopathology later in life.” In another study, young infant rats that received less care and grooming from their mothers were more fearful and anxious. These effects were lifelong and were caused in part by epigenetic changes to genes affecting their glucocorticoid receptors (Weaver et al 2004). Similarly, maternal-infant separation also affected the epigenome in rhesus monkeys, with different amounts of DNA methylation in both prefrontal cortex and T cells (Provençal et al 2012).

In children, neglect and a lack of adult attachment in infancy has been associated with a range of developmental delays.  Romanian institutionalized children who lacked attachment with an adult since infancy showed delays in cognitive function, motor development, language, as well as socio-emotional behaviors. They also had more psychiatric disorders and altered of EEG patterns. Fortunately, some of these deficits were reversible if children were placed into quality foster care at younger ages within a critical age of development.

However, for children who face a range of adverse experiences, some effects can last for a lifetime. In one sample of 132 older adults (average age of 69), adverse childhood experiences – including abuse, loss of a parent, or lack of at least one close relationship with an adult – were correlated with a range of physiological effects including shorter telomeres, which is associated with premature aging (Kiecoty-Glaser et al 2011). British and Finnish children who were evacuated to safer areas during World War 2, but who were separated from their families, grew up to have higher risk of depression and clinical anxiety (Pesonen et al 2007; Rusby and Tasker 2009), and a higher risk of cardiovascular disease and type 2 diabetes (Alastalo et al 2009).

Adjusted odds ratios for cardiovascular disease and type 2 diabetes among Finnish adults who were evacuated as children during WW2 and separated from their families (Alastalo et al 2009).



The deliberate separation of children from their parents seems cruel and unnecessary in the immediate term. In the long-term, it has the potential for negative effects on health and biology, particularly if separated at younger ages. In fact, an online petition from the group Concerned Scientists on Migrant Child Separation has compiled a more complete list of the traumatic effects of early child separation and called for an end to the policy. Some children from Central America may arrive already unaccompanied, without a parent present. I imagine that deciding to send a child alone was very difficult, and in most cases is probably a measure of desperation. There is no need to add to the problem. Additionally, the UNHCR reminds us that “seeking asylum is not illegal under international law and people have a right to be treated humanely and with dignity.”

Finally, to return to Viet Thanh Nguyen, he concluded his essay by wondering aloud what it says about a powerful country like the United States that it is willing to inflict suffering on poor parents and children arriving here:

“I wonder whether whoever decided to take me from my mother considered her pain. Maybe they only saw her alienness and her lack of education, which happened because she was born poor and a girl. Perhaps they never saw that in Vietnam she had been a successful businesswoman. But even if she hadn’t, what difference should that have made? Are people who are less successful not human or deserving of the right to hold on to their children? Our answer to that question says everything about us.”



Alastalo et al. 2009. Cardiovascular health of Finnish war evacuees 60 years later. Ann Med  41:66-72. Link

Goodall J. 2010. Through a window: My thirty years with the chimpanzees of Gombe. Houghton Mifflin Harcourt. Link

Harlow HF, Dodsworth RO, Harlow MK. 1965. Total social isolation in monkeys. Proceedings of the National Academy of Sciences. 54(1):90-7. Link

Holt-Lunstad J, Smith TB, Layton JB. 2010. Social relationships and mortality risk: a meta-analytic review. PLoS Med. Jul 27;7(7):e1000316. Link

Janetsian-Fritz SS, Timme NM, McCane AM, Baucum AJ, O’Donnell BF, Lapish CC. 2018. Maternal deprivation induces alterations in cognitive and cortical function in adulthood. Translational Psychiatry 8 (1) Link

Kiecolt-Glaser JK, Gouin JP, Weng NP, Malarkey WB, Beversdorf DQ, Glaser R. Childhood adversity heightens the impact of later-life caregiving stress on telomere length and inflammation. Psychosomatic medicine. 2011 Jan;73(1):16. Link

Lieberman, M. D. 2013. Social: Why our brains are wired to connect. Oxford. Link

Silk JB, Beehner JC, Bergman TJ, Crockford C, Engh AL, Moscovice LR, Wittig RM, Seyfarth RM, Cheney DL. 2010. Strong and consistent social bonds enhance the longevity of female baboons. Current Biology, July 1 Link

Pesonen AK, Räikkönen K, Heinonen K, Kajantie E, Forsén T, Eriksson JG. Depressive symptoms in adults separated from their parents as children: a natural experiment during World War II. 2007. American Journal of Epidemiology. 166(10):1126-33. Link

Provençal N, Suderman MJ, Guillemin C, Massart R, Ruggiero A, Wang D, Bennett AJ, Pierre PJ, Friedman DP, Côté SM, Hallett M. 2012. The signature of maternal rearing in the methylome in rhesus macaque prefrontal cortex and T cells. Journal of Neuroscience. 32(44):15626-42. Link

Rusby JS, Tasker F. Long-term effects of the British evacuation of children during World War 2 on their adult mental health. Aging and Mental Health. 2009 May 1;13(3):391-404. Link

Weaver IC, Cervoni N, Champagne FA, D’Alessio AC, Sharma S, Seckl JR, Dymov S, Szyf M, Meaney MJ. 2004. Epigenetic programming by maternal behavior. Nature neuroscience. 7(8):847. Link

One thought on “The Scars of Cruelty: Biological Effects of Parent-Child Separation

  1. Pingback: Most Americans Disagree with the Policy of Parent-Child Separation (But Not All) – Patrick F. Clarkin, Ph.D.

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