How does the author use symbolism in the short-story collection, The UnAmericans?

One example of symbolism can be found in the story, A Difficult Phase, in which Talia climbs the palm trees on the kibbutz, and in both the past and present, experiences minor but painful injury as a result of being pricked by the tree's thorns. These thorns represent the experiences of being painfully "pricked" by life and of having the poison in the spines (i.e. the "poison" associated with life) eventually numbing the initial pain.