“…Social causation hypothesizes that better social support ( Seeman, Lusignolo, Albert, & Berkman, 2001 ) and larger social networks ( Béland, Zunzunegui, Alvarado, Otero, & Del Ser, 2005 ) retard cognitive decline, aligned with social integration theory reviewed by Berkman, Glass, Brissette, and Seeman (2000) . Conversely, health selection operates if cognitive limitations affect quantity ( Aartsen, van Tilburg, Smits, & Knipscheer, 2004 ) and quality ( Gurung, Taylor, & Seeman, 2003 ) of social relationships, due to reduced social functioning ( Washburn, Sands, & Walton, 2003 ) and diminished social reciprocity ( Lang, Wagner, & Neyer, 2009 ). The direction of health selection effect is unclear.…”