Nowadays relationship with family is not the only one key element in our happiness. I believe that good terms with work colleagues or classmates is also important and can give emotional support.
First of all, it is more likely that an average person spends more time outdoors, rather at home now. It could be work, university or even school. Most commonly, study or work somewhere includes collective projects, additional tasks or extra hours, so it is more time which people spend with their colleagues. There is also a chance to see someone from work or academy by the way there and back. Happiness not only consist of something unusual such as travelling, receiving presents or celebrating holidays, but it is also about daily routine. It means that good relationship with people you spend the most time makes more reasons to take positive emotions from work.
Secondly, while you work at the same company or study at the same department with someone, you have people with same interests and problems. It is more probably that this type of men will understand you more. Sometimes it is difficult for family members to support you, because it is just something they had not deal with. You can ask your parent for advice, but would it be as effective, as it could be, if it was from comrade in a common cause?
In conclusion, I agree that our happiness depends on our family relationship with the same potency, as the connection with classmates or employees, because emotional health can make your physical and brain work more productive. Sometimes it is more practically to ask for a support from your friends from study, as it could be more meaningful for you.