Answer:
I love that book (the movie is meh)
Step-by-step explanation:
everyone in the "community" are very similar. everyone gets the same thing at the same time, wears the same things, all see black and white, all are assigned jobs with no say in what it is, everyone has to act the same way, etc. I could go on for days.
In summary, everyone has to act the same way and do/get the same things (excluding jobs and gender-appropriate behavior.)
I could explain more in the comments if wanted.
Hope this helps you :)