Is it healthy to have my hair braided tightly?

Most people's hair is the most delicate at the hairline. The hairline is usually the slowest to grow back. You know that your braids are too tight when your scalp develops a lot of tiny bumps and you can see the stress and tension at the root of your hair. This is the scalps defense against your hair being ripped out in large quantities. These are the signs that you scalp is sending you because it can't hold on to the hairs much longer.

-If you look closely at the hairline of these children below, you will see the small bumps that indicate stress and tension. 

-The very last picture is hair loss from the stress and tension of tight braids at her hairline. 

So, you tell me...is it healthy to have your hair tightly braided?