Each age group is given a different developmental gift, including a bicycle at age 9 and a job at age 12.
In the tightly controlled community of The Giver, Sameness is a priority. All children are part of the same age group, rather than celebrating individual birthdays. This way, no one is ever singled out
Jonas is apprehensive when the book opens, because he is approaching the last ceremony.
"You know," his father finally said, "every December was exciting to me when I was young. And it has been for you and Lily, too, I'm sure. Each December brings such changes." (ch 2, p. 11)
At twelve, children are singled out and given an assignment. This will be the job they train for, and their job for life. After that, they are no longer considered children.
All babies born in a year turn One at the same time, regardless of when the baby was born. The Ceremony of One is important because children receive their name and their family. They join a family unit with a man and a woman, and possibly an older child. The parents and children are tightly matched, because they do not have their own children. All children are created artificially and come from Birthmothers.
The ceremonies of younger children mostly involve changes in clothing. At Seven, they get a jacket that buttons down the front to teach them independence.
Fours, Fives, and Sixes all wore jackets that fastened down the back so that they would have to help each other dress and would learn interdependence. (ch 6, p. 40)
At nine years old, they get a bicycle, a "powerful emblem of moving gradually out into the community, away from the protective family unit" (p. 41) and the main mode of transportation in the community for children and adults.
At Twelve, the children are each singled out and the Chief Elder says a speech about the age group and each child. It is the only time differences are celebrated. Each child is carefully observed in the years coming up to twelve and a committee assign the job.
The “gifts” are important because they acknowledge life stages that every child passes through together. There is no individual choice, from hairstyle to clothing. Every choice is made for them, so that everyone remains the same, and there is no discomfort because people are different.
Lowry, Lois (1993-04-26). The Giver (Newbery Medal Book). Houghton Mifflin Harcourt. Kindle Edition.