In the Rockwell painting, the meal has not yet begun, so the scene is filled with anticipation, as people on both sides of the table lean joyfully toward one another, and everyone seems interested and engaged. But this togetherness is hard to create. We have friends whose middle-aged son has a mental disability. He routinely creates a scene and storms out of the family dinner before the meal ends. My in-laws had an uncle with mental illness who lived on the street. Some Thanksgivings, they visited him on his corner; he refused entreaties to accept help. Millions of families include alcoholic members who sometimes become belligerent. In others, narcissists dominate the conversation.

Of course, extended families often include kind, generous people who make us laugh, defuse tense situations and make extraordinary efforts to make everyone feel welcome. They are a key part of the “glue” that makes holidays work. Many families have strategies to keep holiday gatherings successful. Those with members on the autism spectrum plan ahead, by setting aside a quiet space or making sure to prepare familiar foods for someone who has difficulty with a change in routine. Others opt for tech-free dinners to minimize distractions. Most engage in rituals that help family cohesion, such as playing board games or charades, taking walks after dinner, or watching football playoffs or favorite movies.