Adults express anger through many different channels, often using a combination of words, nonverbal utterances, facial expressions, gestures and impatient actions. The infants were observed to show distinct facial expressions of anger, comparable to those seen in adults. Facial expressions of anger are also shown by older toddlers when they encounter frustrating circumstances. In contrast to fear, which is manifested by attempts to escape from or avoid challenging situations, some emotion theorists see anger as an ‘approach-related affect’, which induces people to confront and deal with the frustrating or challenging situation that is eliciting their anger. However, while sibling conflict may have some positive effects, children’s intense anger with their siblings can also be a harbinger of future problems. Some researchers have tried to study what young infants feel on the inside when they are frustrated or expressing anger. The successful regulation of anger is thought to be related to broader self-regulatory abilities, which develop rapidly during early childhood.