Educational DVDs may hinder rather than help a young child's learning. Infants who watch DVDs such as "Brainy Baby" and "Baby Einstein" know fewer words than those who do not watch such programmes, a new study suggests.

In recent years the popularity of such infant programmes has soared, particularly in the US. Parents hope the programmes, which typically consist of brief dialogue and picture sequences, will boost the learning ability of children as young as eight months old, even though the American Academy of Pediatrics has recommended that youngsters not watch television until two years of age.