Final answer:
Trait theorists suggest that children's temperaments are partially innate but can be shaped by environmental influences and maturation throughout middle childhood, focusing on two main dimensions: reactivity and self-regulation.
Step-by-step explanation:
According to trait theorists, the nature of temperament during middle childhood is influenced by both biological and environmental factors. Temperament refers to innate behavioral and emotional traits that appear early in life, such as being easygoing, difficult, or slow to warm up to new situations. Over time, however, factors such as family interactions and maturation can modify how these temperamental traits are expressed in children's personalities.
There are two critical dimensions of temperament that continue into adulthood: reactivity and self-regulation. Reactivity is about how individuals respond to new or challenging environmental stimuli, while self-regulation concerns the ability to control that response. These dimensions shape our temperaments and ultimately contribute to our overall personality in complex ways.