The basic emotions expressed in jealous interactions are fear , anger , relief, sadness , and anxiety. The social triangle involves the relationships between the jealous individual and the parent, the relationship between the parent and the rival, and the relationship between jealous individual and the rival. In a study by Volling, four classes of children were identified based on their different responses of jealousy to new infant siblings and parent interactions. They are anxious to explore the new environment as they tend to seek little comfort from their parents. These children have an intense interest in parent-infant interaction and a strong desire to seek proximity and contact with the parent, and sometimes intrude on parent-child interaction. They have difficulty regulating their negative emotions and may be likely to externalize it as negative behaviour around the newborn.