For over 75 years, psychologists and psychiatrists have known that abrupt and/or prolonged separation can have major implications, including depression, anxiety, and behavioral disturbances. In 1952, Bowlby & Robertson argued, “There is now evidence that prolonged periods of maternal deprivation in very young children can, in some cases, give rise to extremely serious psychiatric disturbances.” In more recent years, we have learned that such separations can also impact brain development, learning, and physical health

During prolonged separations, children progress through three phases: protest, despair, and then detachment. These effects can be observed even when children experience prolonged separation for relatively routine reasons, and can occur when children are well-fed, housed, and looked after during the separations.

The negative impact of separation can be reduced if there is a familiar, loving, other caregiver present. It can also be reduced when the physical environment remains constant, and when, following the reunion with the caregivers, parents slowly rebuild a sense of security for their children. In contrast, when parents feel helpless or scared at the point of separation, the impact separation has on children’s development can be exacerbated.

When the government separates children from parents, the situation is already emotionally heightened. The physical environment is foreign to the child. No loving aunts, uncles, or grandparents are present to care and comfort the child while the parent is away. The reunion will not occur in an optimal environment. Parents experience desperation during the separation, and, at the time of reunion, will be in no position to comfort as they themselves will be in need of care.

Stopping separations was a must. Recognizing their significance in children’s lives, and aiding in reunification and recovery is now of critical importance.

Why is separation from parents such a source of grave distress?

Because we are hard-wired to feel this way. When social animals, including humans, are separated from their group they are more likely to be preyed upon and less likely to reproduce. Drawing upon a statistical review of 208 laboratory studies, Dickerson & Kemeny argue that almost all social stress is, at its root, related to fear of being excluded from the social group. But, along with a few other primates, humans — and especially young humans — may find separation especially stressful.

We humans do not run to a cave or a den when we are scared. When we are very young, we cry for our parents. Then we crawl to them. Then we run to them. It doesn’t matter if these are “good” parents or not — chances are, they are our best chance of surviving, especially since we have the most prolonged period of physical immaturity (and therefore helplessness) of all species. Being left alone is inherently dangerous, signaling the potential of even more danger to come. If the parent doesn’t come back, how can a young human find food? Seek shelter? Be protected? Of course, in modern times a modicum of care may be provided by the government — but thousands of years of human history course through our brains, screaming danger, danger, danger! Which means that our biology responds.

When we are scared, the least costly way of reducing our distress is through a change in behavior — going to the parent — but if we can’t do that, our body reacts. The sympathetic nervous system kicks into high gear (e.g., heart rate increases) and stress hormones pour out into our bloodstream. Over time, too much exposure to stress hormones changes the architecture of our brains, our levels of anxiety, and our ability to think and learn effectively.

Changes in stress hormones represent one pathway through which separation can have long-term ramifications. Even in rodents — burrowing animals that may not find separation as inherently terrifying — mother-pup separations can lead to lifelong neuroanatomical changes related to memory, stress regulation, alcohol use, and parenting in the next generation. In some studies effects are induced by permanent separations, but in others, days — and even hours — of maternal rodent pup separations have lifelong consequences. Recognizing the ill effects of separation, ethics boards mandate that researchers adhere to certain housing guidelines for separating primate mothers and offspring.

Should we expect fewer protections for undocumented immigrant human families than are accorded laboratory animals?

We turn now to studies conducted by researchers interested in understanding parenting behavior and the ways in which human children cope with distress. These studies often use very short, laboratory separations as a “window” into real-world life. In infancy and sometimes toddlerhood, Mary Ainsworth’s Strange Situation procedure is often used to assess children’s relationship with their mothers or fathers. The Strange Situation procedure involves a series of short separations with children being left alone or with an unfamiliar caregiver for one to three minutes, and the traditional three-minute separations are shortened to one minute (or even 30 seconds) if the child seems to be experiencing excessive distress. As with other human research, use of this procedure requires ethical justification and some have criticized this on ethical grounds — suggesting that the potential scientific gain does not justify the stress induced by this three-minute separation.

Because of the Strange Situation’s scientific power, many of the signatories of this letter have conducted thousands of these Strange Situation experimental procedures — always ensuring that the infants are never truly alone (i.e., monitored via CCTV camera or from a one-way mirror) and that the separation is terminated if the child (or the parent) becomes unduly distressed. In some cases, this means we cut short the separations or, less frequently, even terminate the procedure. We believe it is important to take the child’s behavior into account not just for ethical reasons (though that would be enough) but also because we want to capture the child’s behavior in the face of moderate-and not severe-distress.
The degree to which the child finds the experience upsetting and the extent to which the resultant behavior is reflective of the child’s typical manner of coping is dependent on a variety of factors including cultural norms regarding when a child may be left in the care of others, as well as the child’s recent history: Has s/he had a recent week-long separation from the caregiver?; Has s/he recently been primed to find the experience distressing? Has s/he recently been hurt or ill? This mild separation can invoke protest, crying, enhanced heart rate, and changes in cortisol, which, for children with more difficult backgrounds, may be prolonged. Likewise, as first identified by Mary Main and Erik Hesse, professors at UC Berkeley, when children have previously been exposed to fright in the form of frightening, and even frightened, parental care they are likely to show behavioral disorganization and disorientation, such as staring blankly or turning in circles and falling to the floor.

And sadly, these three-minute-long separations conducted in a room of toys are a far cry from the scenes at the Mexican border.

In 1960 John Bowlby wrote this about a young child’s understanding of separation: “He does not know death, but only absence; and if the only person who can satisfy his imperative need is absent, she might as well be dead, so overwhelming is his sense of loss.”

Older children are also scarred by such experience. The powerful need for connection to attachment figures persists throughout children’s development, with elementary-aged children strongly relying on parents’ psychological availability rather than their near-constant physical presence. School-aged children separated from their caregivers show physiological reactions when they are reunited with them, and the presence of caregivers in situations in which children experience stress helps to calm children’s physiological stress response. By all metrics, the presence and availability of the caregivers is an integral part of emotional security throughout children’s development.

The importance of fairly unbroken contact with parents or established parental figures, especially in times of distress, cannot be overstated. When separation is prolonged, mental, emotional, and even biological scars are to be expected. Even if asylum-seeking is a crime, separating children from their parents is a form of “kin punishment,” the type of treatment found in authoritarian regimes that is antithetical to the United States and also illegal. Recognizing the impact that prolonged separation can have on children obligates us to reunite families as quickly and as supportively as possible, and to ensure that this does not happen again.

This piece is a collaborative effort emanating from the global community of researchers dedicated to understanding the significance of attachment relationships to children, including the voices of:

Co-authored by Alicia Lieberman, Anna Maria Speranza, Anne Rifkin-Graboi, Carlo Schuengel, Charles Zeanah, Daniel Siegel, Dante Cicchetti, David Pederson, Debby Jacobvitz, Elizabeth Carlson, Erik Hesse, Frances Nkara, Gottfried Spangler, Howard Steele, Jean-François Bureau, Jessie Borelli. Jody Todd Manly, Jude Cassidy. Judith Solomon, Karlen Lyons-Ruth, Kazuko Behrens, Kristin Bernard, L. Alan Sroufe, Marian Bakermans-Kranenburg, Marinus van IJzendoorn, Mary Dozier, Mary Main, Mary True, Miriam Steele, Naomi Bahm, Pasco Fearon, Pehr Granqvist, Peter Fonagy, Robbie Duschinsky, Robert Weigand, Ruth Goldwyn, Samantha Reisz, Sheree Toth, Sheri Madigan, Sophie Reijman & Susan Spieker.

This article was originally published on Psychology Today.