Professor Susan Golombok:

When we found this, we were not sure why it was happening but in looking at good quality studies by colleagues in the Netherlands who work in international adoption, it was interesting to us that they found exactly the same pattern of these children at age seven showing an increase in emotional and behavioural problems. These researchers put it down to the fact that internationally adopted children are aware they are adopted, as is everybody else, because they look different from their adoptive parents. They attributed the increase in problems at this age to having to deal with these issues at a younger age than other children.

In terms of our study, we cannot be definitive about why we found this slight increase. I should state these children were still within the normal range. It was a statistically significant increase compared to unassisted conception families but they were not showing clinical levels of problems. The explanation in relation to international adoption made a lot of sense because the children knew they were born through surrogacy, many were in touch with the surrogate, other people knew, they were being asked questions about it and so on. Given that how one is conceived can be an important part of one's identity and the story of one's life growing up, it seemed to make sense that having to deal with these issues at an earlier age could play into the reasons for this blip at age seven. Interestingly, it was a pattern that was replicated with internationally adopted children. I cannot say for sure it was the reason but, theoretically and drawing on related research, it seemed to make the most sense in trying to understand what was going on.