The causes of Individual differences among children are - 

Individual differences among children refer to the variations in physical, mental, emotional, and social traits that make each child unique.Key Points

• Heredity refers to the genetic makeup inherited from parents, influencing aspects like intelligence, physical appearance, and natural abilities.
• Environment includes all external factors like family, culture, schooling, and social interactions, which shape a child’s personality, behavior, and learning patterns.
• These two factors interact continuously to produce individual differences.
• For example, a child may inherit high intellectual potential (heredity) but may only develop it fully with proper schooling and encouragement (environment).

Hence, the correct answer is both Heredity and Environment as both significantly contribute to individual differences among children.