Discuss PGroot's answer to: Why can't my son collect his father's social security after he's 18 if he's still living at home and going to college?

Because the law says so. Social Security benefits end when the child turns 18 unless he is disabled or a full-time student attending a secondary school.  Not a college.

Society expects that when you are 18 and have graduated from high school, you should be able to get a job.  In the military, for example.  That would give you college benefits as well.