The popular belief in Japan that an infant's development is curtailed if the mother works is incorrect, according to results of a recent study by a state-run research institute.

The National Institute of Mental Health said its 16-year study found no evidence that infants not taken care of full-time by their mothers up to the age of 3 are more prone to delinquency in later life than other children.

The institute, based in Ichikawa, Chiba Prefecture, is a unit of the National Center of Neurology and Psychiatry.