Answer to Question 1
All three theories support discontinuity because they believe that children's thinking becomes more sophisticated as they develop and influences what they are capable of at different times. Both Piaget's and information processing theory support universal development because they believe that individuals come into the world with a set of skills and ready to learn specific tasks. Vygotsky's theory differs from both of these theories because his theory is context-specific and proposes that children's thinking is influenced by the sociocultural context in which children grow up. In the nature-nurture issue, Vygotsky leans more toward nurture because he believed that every aspect of a child's development is influenced by their sociocultural context. Information processing theory falls more on the nature side of the nature-nurture issue because our mental hardware and software influence development. Piaget's theory seems to consider both aspects of nature and nurture because children are born with a set of cognitive skills but responses to their actions can influence development. This factor makes Piaget's theory more closely related to Vygotsky's theory.
Answer to Question 2
Only children are more like first-borns because they are more likely to succeed in school, to have higher levels of intelligence, and to have higher self-esteem, which is similar to first-born children. Later-born children tend to be more popular with their peers, but only children do not differ in popularity from other children.
Leininger's Culutral Care Theory
Comparison of Major developmental theories
Theory of Mind
Developmental origin of different classes of fruits.
Sampling Issues
The Two-Factor Theory of Emotion