Do smiling faces change children's minds? Testing evaluative conditioning in 3-6‑year‑olds.

This study examined whether preschoolers form preferences for shapes paired with happy or sad faces (evaluative conditioning) and whether the effect varies with age or with the number of different faces paired with each shape. Sixty-one children aged 3-6 years viewed four neutral shapes during a brief conditioning movie. Each shape was assigned to one of four conditions, in which it was paired with a single happy face, a single sad face, five different happy faces, or five different sad faces. Shape preferences were measured before and after the movie, along with memory for the pairings. Children showed clear pre-existing preferences for some shapes, and the pattern differed by age. After accounting for these starting preferences, two additive advantages emerged (for positive over negative faces and for multiple over single faces) and their combination in the shape paired with multiple smiling faces was the only condition to produce a reliable shift from zero. The other three conditions did not produce reliable change, and children's exact age and memory for the pairings did not predict change. These findings suggest that evaluative conditioning in preschoolers is more selective than typically assumed, with the number of different faces paired with a shape emerging as a key factor. The results also highlight the importance of accounting for children's pre-existing preferences when measuring acquired evaluative learning.