Effects of growing up in an orphanage
According to clinical psychologist Dr Karen Richards, there are issues that could arise from being raised in an orphanage, only to be reunited with family at a later date. These include detachment, emotional loss, guilt, and other adjustment issues.
She also said there could be a mismatch in how a child, after being reunited, may feel about his or her family, and how the family feels about the child.
"It is like these people are strangers," she said.
She said the child may feel anger because he or she could feel robbed of time with family.
"Your family heritage is important," she said.
"She said she kept hearing my name, 'Marvin, Marvin', and she told me I have a strong resemblance to this family that she know."
That evening, Marvin reunited with his family. Today, he is still getting to know his nine brothers and sisters, as well as cousins. He said that, so far, getting to know them has been great, except for when he tries to "chat up" a girl and she turns out to be his cousin.
However, in spite of the happy reunion, Bibbs said he is saddened by how much they missed out on Marvin's formative years.
"[Marvin] has lost so much time in a place he didn't choose to be. The child was actually lost in a system for 20 years of his life."
Nicole Wright, legal policy officer for the Child Development Agency, said the Duncans' story reveals systemic failures in Jamaica and described their years of separation as "foolishness".
"We investigate matters where authorities fail, and these authorities include the police and schools," Wright said.
Wright was unable to give an idea of how many other children might be facing similar displacement, but said "the numbers could surprise us".
Inspector Steve Brown of the Constabulary Communications Network said he would have to verify whether a report was made at the Central Police Station back in 1990.
Meanwhile, Marvin says he blames himself.
"If I didn't walk out, this wouldn't have happened."
Winnifred said she always tells him it wasn't his fault.
"He was only four," she said quietly.
Marvin now lives in Frankfield, Clarendon, with his parents, spending his days on the hillside with his father, farming yams, even though he wants to be an electrician.
"It feels good," he said, his face splitting into the first smile, "being here, with my family."