Do you think that human development science is one of the major thinks you must study to be a good leader , project manager or PMO manager?

yes for sure

Highly developed leadership skills are essential for the effective delivery of business change or any sort. It is key to be able to be able to harness the human capital and ensure that project and programmes are delivered on time, within budget constraints and ensure the realisation of planned benefits.

Of course if you want to be a good leader, you must study human development science,

Studying Human Development Sciece will not qualify anyone to become a leaders. Learders are born, they are not made.  Yes, it can help better understand the people and how they react in different situations.  In my opinion, to be a successful leader one should have good EQ and same goes with Managers.