07/31/2013 09:47 pm ET Updated Sep 30, 2013

Abuse, Adoption and Epigenetics

A recent Guardian article brought to light the harrowing circumstances of parents of adopted children who were left to confront major behavioral problems and violence without adequate institutional support.

Matthew Clore and his wife reluctantly admitted failure when their adopted child was put back into care after struggling for eight years to deal with his increasingly aggressive behavior. They had feared for their own psychological as well as physical well being. This decision was traumatic for both parents and child and not taken lightly. When such situations arise, adequate support -- as was requested by the Clore family -- could make a huge difference to keep a family together. Is there anything that could be done to reduce these situations arising in the first place?

We are bombarded by often contradictory advice on how best to bring up our children. However, scientific evidence is usually lacking and research (from my field of twin and adoption studies) has surprisingly failed to find a clear relationship between family environment and the child's resulting behavior. The exception to this seems to be child victims of severe neglect or trauma at a very young age. In some children it has been found that a strongly negative environment may "switch off" genes involved in the development of empathy via a process known as epigenetics. This is the process by which environment influences the genes -- switching them on and off -- a bit like a light dimmer switch.

These epigenetic changes can have major consequences for an individual's empathy and their capacity to form positive relationships long after the negative environment has been removed -- even affecting future generations. If a grandparent had a traumatic childhood, the health consequences of this can be passed on epigenetically (albeit diluted) not only to their children but also their grandchildren. These offspring are likely to be more antisocial and anxious, even if they were raised in average conditions.

Although the hard evidence for these epigenetic changes across generations so far comes from studies of rats, not humans, similar mechanisms exist in most mammals studied. Michael Meaney in his Montreal laboratory carried out experiments in which two identical strains of rats were separated into two adopted groups, a caring group where babies are licked and groomed regularly and a colder group with low licking and grooming behavior. The result is that while the more cared-for rats showed lower levels of stress, the less cared-for rats suffered epigenetic changes to the genes that affected the levels of the stress hormone cortisol, causing this group to react more negatively and antisocially. Moreover, they found the effect was still detected over three generations. The good news was that the harmful effects could be partly reversed by putting the second generation of pups with "caring" foster mothers (1).

In the human world, the Clores' dedicated efforts to provide a loving environment sadly did not affect the behavior of their child positively. We can only assume he suffered such severe neglect or trauma in the early period of his life prior to his adoption that the changes were hard to reverse.

Simon Baron Cohen, a Cambridge psychology professor and expert in autism, stated in an interview with Time that "there's a strong association between early environmental deprivation and neglect and abuse and later outcome of [borderline personality disorder]." (2)

There is, however, wide variability in children's responses to their environment, so not all children that suffer early abuse go on to develop unsocial behavior later in their lives. This resilience seems to be highly genetic and may explain why in a study of group of Romanian orphans abused as young children, a third suffered no long-term behavioral problems (3).

These new scientific insights into our early environment and resulting emotional malleability (plasticity) that is potentially reversible should help to change some attitudes on adoption. For many children there is a narrow window of maximal vulnerability that is likely to be within the first two years. Leaving these children with abusive, non-empathetic families for too long is likely to create long term behavioral problems and repeat the cycle of abuse in future generations. Moving high risk children to loving caring foster parents as soon as possible, regardless of racial or cultural differences, should be a priority to give them the best chance of a successful integration within their new family and society as a whole.

U.S. National Figures in 2011 show that while most children (54 percent) are adopted below the age of 6, only 2 percent of these were under the age of 1, and only 13 percent of children are available for adoption under the age of 2. These figures are similar to those from the UK in 2010. Although the actual assessment process of parental suitability for adoption in theory should not be longer than six to 12 months, it is often longer (4). While child services increasingly recognize the dangers, the state is in favor of keeping a child with natural parents if at all possible, and the legal processes make removal within a year even in the worst families, virtually impossible.

Clearly, for some kids, timing is not in their favor, and those extra months with abusive parents can make a big difference. In these cases, it is imperative that strong support networks and funding are given to adoptive parents, so as to reduce risk of rejection and a return to care. Although clearly a complex social and scientific issue, the message from recent epigenetic research is simple: Give children lots of hugs and cuddles as early as possible -- this is likely to make them more empathetic caring adults.


1) Zhang TY, Labonté B, Wen XL, Turecki G, Meaney MJ.Epigenetic mechanisms for the early environmental regulation of hippocampal glucocorticoid receptor gene expression in rodents and humans. Neuropsychopharmacology. 2013 Jan;38(1):111-23. doi: 10.1038/npp.2012.149.


3) Rutter M, Kumsta R, Schlotz W, Sonuga-Barke E. Longitudinal studies using a "natural experiment" design: the case of adoptees from Romanian institutions. J Am Acad Child Adolesc Psychiatry. 2012 Aug;51(8):762-70