BABIES who are pacified with dummies grow up to have lower than average intelligence, suggests new research published in The Lance. The "strong association" between dummy use and lower than average intelligence was discovered by researchers during a study intended to establish whether breast feeding has an effect on IQ. Pushed to explain why the pacified babies grew up to be less intelligent, researchers suggested that dummies render infants less receptive to outside stimuli that might develop their intellect. They also theorised that parents who use pacifiers to keep their babies quiet are not interacting sufficiently with them.
The researchers, at the Medical Research Council Environmental Epidemiology Unit at Southampton University in the UK, tested the IQ of nearly 1,000 men and women born between 1920 and 1930 in Hertfordshire. Health visitors had kept unusually detailed records for these people which showed not only whether they were fed by bottle or breast, but also whether they were given dummies.
IQs were tested on a 50 point scale and the average score of the subjects now in their 50s and 60s was between 22 and 23. While there was no evidence that breast milk promoted higher intelligence, those adults who as babies had sucked dummies scored four points lower than average. This lower result remained even when the results were adjusted for the influence of lower social class, which itself was linked to the greater use of dummies.