Concepts are the initial thought forms...we build up certain concepts and begin putting them into relation to our lives. Some we throw out, and some we continue buidling upon, thinking and working out in our heads (and computers nowadays) how we can manifest the concepts into our reality...then, we actually begin manifesting our thoughts turned to concepts as we work out how and if they will be benificial to our physical lives. We begin building the concepts into our physical reality and the constructs are born.
We don't have to literally build the concepts into constructs like a building, but, like religions and philosophies and 'law systems', we build them through communication. When they reach a particular tipping threshold, the collective begins reacting these communicated concepts as if they are a reality, and the communicated concepts become constructs in our lives...we build entire governments and civilizations around the constructs.
Science, religion, philosophies, education, etc are the major constructs...they are the paradigms...or a collective cohesion and working order of multiple constructs.
That is why paradigm change is so difficult. We are embedded in all this...everywhere. And in order to break down a paradigm, many multiples of constructs must constantly be broken down. In order for that to happen, other thoughts must take root, forming the concepts...and with enough influence behind them, they form cracks in the existing paradigms. But, as you can see, it is a monumental task, as others who do not want paradigm transformation are repairing the damage to the existing paradigms with all their might.
So, you get revolutions of sorts, where the influence is great and strong, punching cracks in the existing paradigms, quick, hard and constant...persistent.
Then the collapse happens, and the world shifts...