Children neglected in their childhood are likely to develop abnormal behaviour, says a study.
Psychologist Seth Pollak and doctoral student Alison Wismer Fries at University of Wisconsin-Madison studied 18 four-year-old adoptees, who had spent their first years in orphanages in Russia and Romania, mostly in a neglected environment.
Even though the children now live in stable homes for over three years, in some cases - they might still display some telltale behaviors that researchers associate with early neglect, the researchers said.
One is an abnormal willingness to seek comfort from unfamiliar adults, even in the presence of the adopted parent.
The scientists tracked the levels of two "social" hormones, called vasopressin and oxytocin, in the children through urine tests.
The researchers said they immediately noticed that the children who experienced early neglect had markedly lower levels of vasopressin than non-adopted children.
They think vasopressin is essential for recognizing individuals in a familiar social environment.
The researchers said that in family-reared children, oxytocin levels go up following physical contact with their mothers.
But in the neglected group, the levels stayed the same. Because oxytocin is necessary for forming secure relationships, this might help explain why many neglected children have trouble doing so, the scientists said.
"It's extremely important that people don't think that this work implies these children are somehow permanently delayed," said Seth Pollak, senior author of the study.