I like 2 sections the most.  

How society or societies play a major part in how we learn or adapt our behaviors and how it serves to block selfish and instinctual behaviors.  

I also think society can play a part in bringing those behaviors to the surface on a microenvironment level. 

Some examples would be mob mentality,  Gang participation, social economic deprivation, and rhetoric separatism. ( Sorry if the terms are not 100% correct) 

Maslow's Hierarchy of Needs and where an individual is on it, can also play a huge factor in how we as human beings react to one another.

I also liked the section that spoke on the interview process. Use of the 2 types of questioning.

 Open questions

Projective questions

I can see this also being used in online marketing a lot.  As in regular advertising dating all the way back to the early 20s.

A good example would be:

The psychology of selling and advertising, by Edward K. Strong