Along with physical and cognitive development, every child progresses through phases of emotional development. Arguably, all children differ in their individual development. Studies have shown that parents admit to having little information on emotional development, even though they also admit that their actions have great influence on their children's emotional development.
Emotions are not as easy to study or recognize as cognition, and for many decades the study of emotional development lagged behind study in other areas of child development. However, by the early twenty-first century researchers had developed several theories on emotional development.