The white social worker looked at the dark spots on the black child's body and makes a blunder.
It turned out the child had "Mongolian spots" - harmless skin blotches common among black children. The social worker's mistake was discovered before the parents got into trouble.
But researchers and policymakers say such episodes help explain why black, Hispanic and other minority children in the United States are far more likely than white youngsters to be taken from their homes and placed in foster care.
Racial or ethnic prejudices - conscious or unconscious - can lead social workers to see abuse or neglect where none exists, these experts say.
The experts caution that stereotyping on the part of social workers is just one factor in the racial gap, and probably a small one at that. Other factors - higher rates of poverty, inadequate housing and child care, for example - are believed to be major contributors to abuse and neglect among minorities.
Nevertheless, stereotyping is enough of a concern that cultural-awareness training for social workers has been instituted in 45 of 50 U.S. states, many of them in the just the past few years, according to a recent report by the Government Accountability Office, the investigative arm of Congress.
In the United States, blacks make up about 15 percent of the childhood population, yet account for 34 percent of children in foster care, according to the GAO report. Black children on average stay in foster care nine months longer than white children, the report said.
The report said "bias or cultural misunderstandings and distrust between child welfare decision makers and the families they serve" was one of several factors accounting for the gap, along with poverty and lack of access to services.
"Once we are reported, we are more likely to be investigated. Once we are investigated, we are more likely to be placed in foster care. Once we are placed in foster care, we are less likely to be returned to our families," said Sondra Jackson, executive director of Black Administrators in Child Welfare.
In overwhelmingly white Utah, black children were in foster care at more than six times their proportion of the state's population, according to the GAO. In five other states - Wisconsin, Iowa, New Hampshire, Wyoming, and California - black children were four times more likely to end up in foster care.
In Massachusetts, 7 percent of children are black, but 19 percent children in state care are black. Hispanics are 11 percent of the child population but 25 percent of those in foster care. White children are 79 percent of the population, but just 60 percent of those in state care.
"People come with biases and how those racial biases play out is of real concern," said Bill Brown, area director for the state Department of Social Services in Boston.
The problem is not just black and white.
When Vietnamese and Cambodian immigrants began moving in large numbers to Lowell, a mill city outside Boston, social workers started hearing troubling reports of children with odd, circular marks on their bodies.
"Our first reaction was that the children were being battered or bruised or spanked," said Zevorah Ortega-Bagni, a state social services investigative supervisor.
Social workers were actually seeing the effects of a traditional healing practice known as "cupping," in which a cup is heated and placed on the skin to draw out illnesses. Far from abuse, the marks were a sign that parents were doing their best to care for their children.
Researchers say minorities are no more likely than whites in similar socio-economic circumstances to abuse or neglect their children. But minorities are more likely to be poor, with blacks nearly four times more likely to live in poverty than others.
Kandida Garcia, a child welfare investigator in Massachusetts, said her Puerto Rican background gives her an edge when dealing with parents of a similar background - especially in emotionally charged situations.
"Another worker may target them as explosive because they are loud in nature, but I would have a different view," she said. "I could explain that this mother is not being aggressive; she is advocating for her child."
In Massachusetts, one of the states to adopt cultural training, the 2,800 social workers and supervisors are shown videos, engage in role-playing and talk about their own heritage and their assumptions about others. An Associated Press reporter asked to sit in on a session but was denied for fear it would inhibit open discussion.
However, the GAO found there was little evidence that such "cultural competency" programs have helped.
Other strategies to reduce the gap include creating multicultural teams of social workers, recruiting minority families as foster parents, and relying more heavily on "kinship caregivers" - aunts, uncles or grandparents who can step in during a crisis.