Why do babies like what they like?

Why does your baby like that particular scrappy grey rabbit that is no longer really grey and has almost lost one of its ears? You might wonder how that strong preference for a particular object came about? ​

New research from our lab shows that infants’ preferences for objects can be manipulated by pairing emotional stimuli with initially-neutral objects, a process that is known as evaluative conditioning.

In these studies, we showed 6- to 7-month-old babies were shown images of two different objects like the blue square and a yellow triangle shown below

On each trial, one of these objects was shown on a screen at the same time as a picture of a happy face, while the other was presented at the same time as an angry face. These object emotion pairings were shown over and over again until the the infants were bored of looking at them. Throughout this learning phase,  we used an eye tracker to record where the babies were looking. 

After the learning phase was completed, we showed the babies pictures of the two objects on the screen at the same time, and then gave them the opportunity to “tell” us which of the objects they like best by choosing one or the other. 

Overall, we found that more babies chose the object that had been paired with happy faces than the object paired with angry faces, however, where babies were looking during learning predicted which object they would choose. Babies who looked more at the faces than at the objects were more likely to chose the object that was associated with the happy face, whereas babies who looked equally at the faces and object seemed to choose randomly.  
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We replicated this effect in a second study in which the same objects were paired with either pictures of  the baby’s mother, or a picture of a stranger. Again, more babies picked the object that was paired with their mum than with a stranger and the amount of time they spent looking at the faces predicted which object they chose. 

Our research show that infant’s preferences for objects may come about via simple associative learning processes. Infants come to like objects that are associated with positive affect (happy faces; pictures of their mum), however, this kind of learning depends on how much time infants spend looking at the source of that emotion (i.e. the face). 

As for that rabbit, you probably smile at your baby as you lay them in their cot and hand them the rabbit at bed time. It’s possible that they like it because they have learned to associate it with you, their favourite person in the world. 
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Eve Whitwell

Research Assistant