What are the motifs in The Monstrumologist by Rick Yancey?

A recurring idea in the novel is the emotional connections of the characters in the novel, and their desire to have personal connections. Will Henry's parents have passed away, and his only companion, Dr. Warthrop, is difficult, at best. He seems to notice Will little, and doesn't particularly seem to show love, care, or compassion as some do. It becomes clear through the novel that Dr. Warthrop does love Will, in his own way, but he has no idea how to show that love.