The sound of babies crying is uniquely able to get adults to react at speed, Oxford University researchers have found.
They compared the scores of 40 volunteers on the classic arcade game 'Whack-a-mole' after listening to babies crying with their scores after hearing sounds of adults in distress or birdsong similar in pitch and variability to infants' cries.
The participants’ scores were higher after listening to the sound of crying babies. Men and women had similar scores overall.
'Whack-a-mole' requires people to hit one of nine buttons, reacting as quickly as they can to whichever of the buttons lights up at random. It is a game that requires speed, accuracy and dexterity.
The researchers say that faster reactions may help us in responding to babies in distress. Professor Morten Kringelbach, who together with Professor Alan Stein led the work in the Department of Psychiatry at the University of Oxford, says: 'Our findings suggest that baby cries are treated as "special". Neither adult cries nor birdsong produce the same response.
'The improvements in speed and dexterity may reflect an evolved response that kicks in when an immediate reaction to a baby in distress is required. It is not hard to see how this could facilitate care-giving behaviour.'
The study is published in the journal Acta Paediatrica and was funded by the Wellcome Trust, the UK Medical Research Council and the TrygFonden Charitable Foundation in Denmark.
Previous research has shown that the sound of crying babies produces a physiological response in adults, seen in a higher heart rate, blood pressure and hand grip strength.
This new work shows that this is likely to be part of a 'high alert' state where adults are primed to react rapidly to a baby’s distress.
'Few sounds provoke a visceral reaction quite like the cry of a baby,' says Professor Kringelbach. 'For example, it is almost impossible to ignore crying babies on planes and the discomfort it arouses, despite all the other noises and distractions around.'
He adds: 'This is not just of academic interest. Our work is showing that in mothers with postnatal depression, through no fault of their own, this response may be disrupted to some extent. Depression and postnatal depression may result in some people not attending so much to babies' cries. We are looking at whether interventions can make a difference to this.'