The four factors considered in Matching of Spouses are “disposition, energy level, intelligence, and interests.”
In Jonas’s community, everything is tightly controlled. People do not grow up, meet and fall in love, and start families. Instead, a family unit is created when two adults apply to be matched. There is no love involved. A committee determines who will be paired, for the sole purpose of raising two children who are not their own.
The committee gives “weighty consideration” to the Matching of Spouses (ch 6, p. 48). Jonas notes that some people are not given spouses, such as the night crew nurturers.
Most of the people on the night crew had not even been given spouses because they lacked, somehow, the essential capacity to connect to others, which was required for the creation of a family unit. (ch 1, p. 8)
Therefore not everyone gets a family. The committee has to match spouses first, and then assign children—one boy and one girl. The factors of “disposition, energy level, intelligence, and interests” (ch 6, p. 48) are considered carefully before matching a couple. Basically, they have to have similar personalities, levels of smartness, activities and interests, so that they get along and can be good partners for raising children.
Lowry, Lois (1993-04-26). The Giver (Newbery Medal Book). Houghton Mifflin Harcourt. Kindle Edition.