Which of the following is NOT a principle of development?

The statement that development is universal and unaffected by cultural contents is NOT a principle of development. While there are universal aspects of development, cultural contexts significantly influence how, when, and what develops. Cross-cultural research clearly shows that cultural practices, values, and tools shape developmental trajectories. The other options - that development is lifelong, modifiable, and influenced by both heredity and environment - are well-established principles.