Psychological development refers to the growth and changes that occur in a person's mental processes and behaviors as they age and experience different life events. This development is influenced by a combination of genetic factors, environmental factors, and personal experiences. During different stages of psychological development, individuals acquire new skills, capabilities, and ways of thinking, which shape their behavior. For example, during childhood, individuals may develop the ability to regulate their emotions and interact with others, which can impact their social behavior and relationships.