One of the fascinating things about taking a neuroscience class as well as a developmental psychology class is you get a glimpse into this fascinating conversation from the profs/lectures/textbooks when alternating between them.

Psych: This Is Exactly Why This Happens, In The Brain, And The Muscles
Neurosciences: Yeah we don't know that at all actually
Psych: This Neurological Structure Can Make This Happen
Neurosciences: Yeah that's not even an educated guess
Psych: We Can Measure This
Neurosciences: Not even close, bub