Answer:
hierarchy of motives
Explanation:
The professor is explaining a theory well known as Maslow hierarchy of needs or motives.
Since any motive will have an unobservable inner component, it will stimulate and act based on a direction or response for which there is a bottom line:
The physical safety, like having a place to rest and protect form the environment, just as having food will always precede social needs.
When a need is met another motive will be sought, dwellers seeking friendships will engage in this as part of social needs.
If all feel having security and well being social needs will enable people to interact to fullfill, after which some other needs like love, can emerge.
Further motives and needs arise as previous are being fulfilled.