Study Search Results Your query returned 2 results. Series results are grouped under the most relevant study. You can ungroup series results. Results per page: 25 50 100 Sort by: Study Relevance Title A-Z Released/Updated Time Period Most Cited in ICPSR Bib. Variable Relevance (?) Study Title/Investigator 1. National Survey of Midlife Development in the United States (MIDUS II), 2004-2006 (ICPSR 4652) Ryff, Carol; Almeida, David M.; Ayanian, John S.; et al. 6 more results in Midlife Development in the United States (MIDUS) Series 2. Social Networks in Adult Life, 1980: [United States] (ICPSR 9254) Kahn, Robert L.; Antonucci, Toni C.