Some interventions sound as if they just have to work simply because they strike the right chord in the popular imagination.

Family Group Decision Making (FGDM), which draws on the strengths of traditional Maori family culture, attracted zealous support when it migrated to Europe and the US from New Zealand 20 years ago.

It originated in the collective efforts of Maori community leaders and government officials to remedy the overrepresentation of Maori children in the country’s welfare system, and its supporters hallowed the family-oriented approach as a welcome revolution in child welfare practice.

Its focus on the concerns and strengths of the family and the embrace it extended to everyone with an interest in the well-being of a child fitted with an optimistic view of the strength of the family unit as a source of wisdom, safety and protection. But despite FGDM’s gut appeal, hard evidence of its effectiveness remained elusive.

And now new findings from an all too rare randomised allocation study concentrating on two communities in California indicate that its benefits over other more standard intervention approaches are at best unremarkable.

Stephanie Cosner Berzin, the author of a recent article in Children and Youth Services Review, notes that few studies had previously examined the impact of FGDM on children. What studies did exist had been less than rigorous. For example, many of them looked at their effect on only a small number of children.

Her study involved more children than past studies by looking at all of the siblings in families involved in the programs. She was able to compare 197 children of families randomly assigned to receive FGDM to 126 children of families assigned to receive standard child welfare services.

Specifically, she looked for differences between the two groups in incidents of child maltreatment and how long children who were place in foster families (or other types of care) stayed in those situations.

Both groups did about the same.

Before concluding that FGDM has little to offer, Berzin suggests considering whether it might have a more immediate effect on 'intermediate outcomes', such as improving the relationship between county and family and the quality of family communication, which, in turn, might eventually affect children’s safety and stability.

She also notes that social workers in one of the two counties worked with both FGDM families and families who received traditional services. She acknowledges that these workers might unknowingly have applied some of the FGDM philosophies to families in the other group – which might account for the lack of difference.

Still, the findings, which reflect those of less rigorous studies, should not be ignored. Policymakers and practitioners should keep alert not only to what makes apple-pie sense, but what actually makes a difference.