Plz, explain what does it mean?
Psychologists have found that the number of social contacts we have is not the only reason for loneliness.
It is more important how many social contracts we think or expect we should have.
What does the part of 'we think or expect we should have' mean?

Question

Plz, explain what does it mean?
Psychologists have found that the number of social contacts we have is not the only reason for loneliness. 
It is more important how many social contracts we think or expect we should have. 
What does the part of 'we think or expect we should have' mean?

Answer

If I invite you over to my house for dinner you would expect or think  that I had food for us to eat.

You would be disappointed if you came over and there was no food because you were expecting food.

or if you had a party and invited 50 people and only 10 showed up you'd feel unliked but if you invited 10 and 10 showed up you'd be happy and feel well liked

If I expect to have 20 social contracts but really have only 10, then I feel more lonely than if  expected 10 and had 10