Temperament traits are based on emotional or behavioral dimensions that develop during early childhood and later on form a basis for personality. Childhood temperament is assumed to reflect biological individuality. Temperament can be categorized as easy, difficult, or a little slower to warm up. These are different areas where children tend to fall into place In this study, they tested 408 different children all around the age of 4.5.
During home visits, a child's temperament was assessed using a Lab-Tab which is a home based temperament assessment that includes behavioral episodes. The children either showed fear, anger, sadness, shyness, etc during the testing. The study concluded that when a child was taken away from the room that had toys, they were sad when they returned to the room and realized that they were unable to touch the toys. When a child was in a negative environment, they had a negative behavior. When they were in a positive environment, they elicited a positive behavior.
Gagne, J. R., Van Hulle, C. A., Aksan, N., Essex, M. J., & Goldsmith, H. H. (2011, June). Deriving childhood temperament measures from emotion-eliciting behavioral episodes: Scale Construction and initial validation. Psychological assessment. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3115493/