The _____ principle refers to the fact that, with development, ...

[D2AR0N]

The _____ principle refers to the fact that, with development, humans tend to become more differentiated and show greater hierarchical integration.
 
  Fill in the blank(s) with correct word

Question 2

The fact that the ability to control one's head develops before the ability to control one's legs illustrates the _____ principle.
 
  Fill in the blank(s) with correct word

[chreslie]

Answer to Question 1

orthogenetic

Answer to Question 2

cephalocaudal