In the opening paragraphs of "A Visit to Grandmother," Chig immediately recognizes that there is something wrong when he watches his father kiss his mother. For, his father's demeanor is inconsistent with the way in which he usually interacts with people.
Chig observes his father as he bends over to kiss his mother after so many years of not having visited--Chig was but a baby when he was first there. As he watches his father kiss his grandmother, Chig sees "fear, uncertainty, sadness, and perhaps even hatred." This observation shocks Chig because he has known his father to always be a warm person. In fact, Dr. Charles Dunford has consistently been able to allay fears in his patients when they enter his examination rooms on their first visits. Indeed, Chig feels that his father is "the warmest of men" who is always able to relax his patients--even get them to laugh. And, for this reason, Chig is perplexed by his father's apparent feelings toward his own mother.
This opening paragraph of "A Visit to Grandmother" introduces the theme of family and the conflicts that often exist in families. That Chig is disturbed by his father's behavior acts as an introduction to the author's theme that family unity is important to the survival of the family itself.